Diagnostics

Herbaceous Ornamentals-Perennials

Anemone (Anemone)

  • Cutworms (Black/Variegated) (Noctuidae family)
    Variegated cutworm larvae have pale-yellow spots on the back of most body segments with a dark W-mark usually present on the 8th abdominal segment. They are usually active at night. Adult moths are ashy, or light dirty brown with dark brown mottling. Pupae overwinter in soil. Moths lay eggs on leaves, stems of plants and possibly on inanimate objects such as fences and buildings. There are usually 2 generations a year. Black cutworm larvae are gray brown to black with a somewhat greasy sheen. They are also nocturnal feeders. 3 generations are common in WI. Adults don't survive Northern winters, but are strongly migratory. Adult moths have a 2" wingspan and are uniformly dark brown with a black daggerlike marking on the forewing. All species of cutworms curl up into a tight "C" when disturbed.
  • Downy mildew (herbaceous) (Several)
    Early symptoms appear as irregular, light green or yellow angular patches on upper leaf surfaces. Lesions may also be purplish red to dark brown. Under high humidity, downy mildews form fluffy or fuzzy (downy) areas of spores on the undersides of leaves. Under magnification, the downy areas look like very small bunches of branched hairs. Older leaves toward the bottom of plants are usually infected first and wither and brown as the disease proceeds up the stem.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Rusts (herbaceous) (Several)
    Symptoms of infection usually first appear as light-colored spots on upper leaf surfaces followed by dry, brown, orange, purple, reddish or yellowish spore masses or pustules commonly on the lower leaf surfaces. Each rust species is specific to a certain host genus or species and cannot spread to unrelated plants. Moderate infections will not harm plants, but can make plants unattractive. Heavily infected leaves may curl, wither and drop prematurely. Severely infected plants may be stunted. Rusts spread primarily via windblown spores.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Bellflower (Campanula)

  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Impatiens necrotic spot (Impatiens necrotic spot virus (INSV))
    Viruses can only be definitively diagnosed in a lab under high magnification or with various serological test kits. Symptoms can include necrotic streaks, spots, rings and lines on leaves and stems; vein necrosis; distorted flowers, stems and leaves; general stunting; and bud drop. Black, brown, reddish or yellowish concentric rings, although not always present, are also symptoms of viral infection. This virus is spread by thrips which feed on infected plants and spread the virus to healthy plants via their saliva.
  • Rusts (herbaceous) (Several)
    Symptoms of infection usually first appear as light-colored spots on upper leaf surfaces followed by dry, brown, orange, purple, reddish or yellowish spore masses or pustules commonly on the lower leaf surfaces. Each rust species is specific to a certain host genus or species and cannot spread to unrelated plants. Moderate infections will not harm plants, but can make plants unattractive. Heavily infected leaves may curl, wither and drop prematurely. Severely infected plants may be stunted. Rusts spread primarily via windblown spores.
  • Slug (Order Sytlomatophora)
    Garden slugs are terrestrial mollusks, essentially snails without shells. As they move, they coat surfaces with a silvery, slimy substance. Most feed at night or during dark, cloudy days. Trails and feeding injuries are usually noticed before the slug itself. Slugs overwinter either as adults or as eggs. They become active during the first warm days of spring, and thrive under cool, damp conditions. Populations will be high during/following damp, rainy weather, and will almost disappear during dry periods. Slugs cannot survive direct sunlight. Rock walls, boards, pots and plant debris, as well as shaded flower beds and heavily mulched gardens, serve as ideal daytime resting sites.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.

Blackberry lily (Belamcanda)

  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Overwatering ()
    Overwatering, whether acute or chronic, is usually a death sentence for plants, especially when accompanied with poor drainage. Waterlogged soils limit oxygen uptake by plant roots, which in turn affects the plant's metabolism, nutrient uptake, water absorption and photosynthesis. Symptoms vary from slow growth to plant death and can include: leaf necrosis, dieback, root discoloration, soil blackening, foul odors, slow growth, thinning canopy and chlorosis. Overwatered conifer symptoms are similar, except they can also exhibit needle drop. Overwatering is common in irrigated landscapes, plantings at the bottoms of slopes and in poorly drained containers.
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Bugleweed (Ajuga)

  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Overwatering ()
    Overwatering, whether acute or chronic, is usually a death sentence for plants, especially when accompanied with poor drainage. Waterlogged soils limit oxygen uptake by plant roots, which in turn affects the plant's metabolism, nutrient uptake, water absorption and photosynthesis. Symptoms vary from slow growth to plant death and can include: leaf necrosis, dieback, root discoloration, soil blackening, foul odors, slow growth, thinning canopy and chlorosis. Overwatered conifer symptoms are similar, except they can also exhibit needle drop. Overwatering is common in irrigated landscapes, plantings at the bottoms of slopes and in poorly drained containers.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Columbine (Aquilegia)

  • Cucumber mosaic (Cucumber mosaic virus)
    Viruses can only be definitively diagnosed in a lab under high magnification or with various serological test kits. Viruses can retard plant growth and change the appearance of foliage, flowers and fruits. Virus-infected leaves can become spotted, streaked or mottled; they may be distorted or stunted. Veins may lose their color or develop outgrowths. Flowers can be dwarfed, deformed, streaked, faded, or they can remain green and develop into leaf-like structures.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Impatiens necrotic spot (Impatiens necrotic spot virus (INSV))
    Viruses can only be definitively diagnosed in a lab under high magnification or with various serological test kits. Symptoms can include necrotic streaks, spots, rings and lines on leaves and stems; vein necrosis; distorted flowers, stems and leaves; general stunting; and bud drop. Black, brown, reddish or yellowish concentric rings, although not always present, are also symptoms of viral infection. This virus is spread by thrips which feed on infected plants and spread the virus to healthy plants via their saliva.
  • Overwatering ()
    Overwatering, whether acute or chronic, is usually a death sentence for plants, especially when accompanied with poor drainage. Waterlogged soils limit oxygen uptake by plant roots, which in turn affects the plant's metabolism, nutrient uptake, water absorption and photosynthesis. Symptoms vary from slow growth to plant death and can include: leaf necrosis, dieback, root discoloration, soil blackening, foul odors, slow growth, thinning canopy and chlorosis. Overwatered conifer symptoms are similar, except they can also exhibit needle drop. Overwatering is common in irrigated landscapes, plantings at the bottoms of slopes and in poorly drained containers.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Common or Rose Mallow (Althaea)

  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Root rot (woody plants) (Pythium species (W))
    Gardeners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggesting a nutrient deficiency. Examination of the roots of these plants reveals tissue that is soft and brown.
  • Rusts (herbaceous) (Several)
    Symptoms of infection usually first appear as light-colored spots on upper leaf surfaces followed by dry, brown, orange, purple, reddish or yellowish spore masses or pustules commonly on the lower leaf surfaces. Each rust species is specific to a certain host genus or species and cannot spread to unrelated plants. Moderate infections will not harm plants, but can make plants unattractive. Heavily infected leaves may curl, wither and drop prematurely. Severely infected plants may be stunted. Rusts spread primarily via windblown spores.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

False spirea (Astilbe)

  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Feather reed grass (Calamagrostis)

  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Rusts (herbaceous) (Several)
    Symptoms of infection usually first appear as light-colored spots on upper leaf surfaces followed by dry, brown, orange, purple, reddish or yellowish spore masses or pustules commonly on the lower leaf surfaces. Each rust species is specific to a certain host genus or species and cannot spread to unrelated plants. Moderate infections will not harm plants, but can make plants unattractive. Heavily infected leaves may curl, wither and drop prematurely. Severely infected plants may be stunted. Rusts spread primarily via windblown spores.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Fumitory (Corydalis)

  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Overwatering ()
    Overwatering, whether acute or chronic, is usually a death sentence for plants, especially when accompanied with poor drainage. Waterlogged soils limit oxygen uptake by plant roots, which in turn affects the plant's metabolism, nutrient uptake, water absorption and photosynthesis. Symptoms vary from slow growth to plant death and can include: leaf necrosis, dieback, root discoloration, soil blackening, foul odors, slow growth, thinning canopy and chlorosis. Overwatered conifer symptoms are similar, except they can also exhibit needle drop. Overwatering is common in irrigated landscapes, plantings at the bottoms of slopes and in poorly drained containers.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Lily of the valley (Convallaria)

  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.

Monkshood (Aconitum)

  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Impatiens necrotic spot (Impatiens necrotic spot virus (INSV))
    Viruses can only be definitively diagnosed in a lab under high magnification or with various serological test kits. Symptoms can include necrotic streaks, spots, rings and lines on leaves and stems; vein necrosis; distorted flowers, stems and leaves; general stunting; and bud drop. Black, brown, reddish or yellowish concentric rings, although not always present, are also symptoms of viral infection. This virus is spread by thrips which feed on infected plants and spread the virus to healthy plants via their saliva.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Overwatering ()
    Overwatering, whether acute or chronic, is usually a death sentence for plants, especially when accompanied with poor drainage. Waterlogged soils limit oxygen uptake by plant roots, which in turn affects the plant's metabolism, nutrient uptake, water absorption and photosynthesis. Symptoms vary from slow growth to plant death and can include: leaf necrosis, dieback, root discoloration, soil blackening, foul odors, slow growth, thinning canopy and chlorosis. Overwatered conifer symptoms are similar, except they can also exhibit needle drop. Overwatering is common in irrigated landscapes, plantings at the bottoms of slopes and in poorly drained containers.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Pigsqueak (Bergenia)

  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Slug (Order Sytlomatophora)
    Garden slugs are terrestrial mollusks, essentially snails without shells. As they move, they coat surfaces with a silvery, slimy substance. Most feed at night or during dark, cloudy days. Trails and feeding injuries are usually noticed before the slug itself. Slugs overwinter either as adults or as eggs. They become active during the first warm days of spring, and thrive under cool, damp conditions. Populations will be high during/following damp, rainy weather, and will almost disappear during dry periods. Slugs cannot survive direct sunlight. Rock walls, boards, pots and plant debris, as well as shaded flower beds and heavily mulched gardens, serve as ideal daytime resting sites.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Rock cress (Aubrieta)

  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Sweet Flag (Acorus)

  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Tickweed (Coreopsis)

  • Cucumber beetle (Spotted/Striped) (Chrysomelidae family (CB))
    Larvae are pale-colored and wormlike with brown heads. Adult spotted cucumber beetles are about 1/4" long, with shiny black heads and greenish-yellow with 12 black spots on their backs. Adult striped cucumber beetles are about 1/4" long, with shiny black heads and are yellowish-orange with 3 black stripes. There may be 1-2 generations of each type of cucumber beetle per year.
  • Downy mildew (herbaceous) (Several)
    Early symptoms appear as irregular, light green or yellow angular patches on upper leaf surfaces. Lesions may also be purplish red to dark brown. Under high humidity, downy mildews form fluffy or fuzzy (downy) areas of spores on the undersides of leaves. Under magnification, the downy areas look like very small bunches of branched hairs. Older leaves toward the bottom of plants are usually infected first and wither and brown as the disease proceeds up the stem.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Impatiens necrotic spot (Impatiens necrotic spot virus (INSV))
    Viruses can only be definitively diagnosed in a lab under high magnification or with various serological test kits. Symptoms can include necrotic streaks, spots, rings and lines on leaves and stems; vein necrosis; distorted flowers, stems and leaves; general stunting; and bud drop. Black, brown, reddish or yellowish concentric rings, although not always present, are also symptoms of viral infection. This virus is spread by thrips which feed on infected plants and spread the virus to healthy plants via their saliva.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Various ferns (Adiantum, Asplenium, Blechnum, Dryopteris, Gymnocarpium, Polystichum, etc.) (Ferns)

  • Animal damage ()
    Animals that do the most damage to herbaceous plants include: deer, rabbits and woodchucks. Deer damage is distinctive because deer only have teeth on their lower jaws, so when they bite down, they must tear the plant to pull off leaves. Thus, deer damage to plants is rough or shredded-looking. It may also be several feet off of the ground. Plus, if a large amount of plant material is damaged overnight, you should suspect deer. Rabbit damage looks like someone used a pruner to cut the plant off at a clean, 45-degree angle. Woodchucks will mow down plants, or sometimes just nibble on succulent material. They are diurnal, so keep on the lookout.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Overwatering ()
    Overwatering, whether acute or chronic, is usually a death sentence for plants, especially when accompanied with poor drainage. Waterlogged soils limit oxygen uptake by plant roots, which in turn affects the plant's metabolism, nutrient uptake, water absorption and photosynthesis. Symptoms vary from slow growth to plant death and can include: leaf necrosis, dieback, root discoloration, soil blackening, foul odors, slow growth, thinning canopy and chlorosis. Overwatered conifer symptoms are similar, except they can also exhibit needle drop. Overwatering is common in irrigated landscapes, plantings at the bottoms of slopes and in poorly drained containers.
  • Slug (Order Sytlomatophora)
    Garden slugs are terrestrial mollusks, essentially snails without shells. As they move, they coat surfaces with a silvery, slimy substance. Most feed at night or during dark, cloudy days. Trails and feeding injuries are usually noticed before the slug itself. Slugs overwinter either as adults or as eggs. They become active during the first warm days of spring, and thrive under cool, damp conditions. Populations will be high during/following damp, rainy weather, and will almost disappear during dry periods. Slugs cannot survive direct sunlight. Rock walls, boards, pots and plant debris, as well as shaded flower beds and heavily mulched gardens, serve as ideal daytime resting sites.
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • White mold (Sclerotinia stem rot) (Sclerotinia species)
    Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.

Yarrow (Achillea)

  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Overwatering ()
    Overwatering, whether acute or chronic, is usually a death sentence for plants, especially when accompanied with poor drainage. Waterlogged soils limit oxygen uptake by plant roots, which in turn affects the plant's metabolism, nutrient uptake, water absorption and photosynthesis. Symptoms vary from slow growth to plant death and can include: leaf necrosis, dieback, root discoloration, soil blackening, foul odors, slow growth, thinning canopy and chlorosis. Overwatered conifer symptoms are similar, except they can also exhibit needle drop. Overwatering is common in irrigated landscapes, plantings at the bottoms of slopes and in poorly drained containers.
  • Rusts (herbaceous) (Several)
    Symptoms of infection usually first appear as light-colored spots on upper leaf surfaces followed by dry, brown, orange, purple, reddish or yellowish spore masses or pustules commonly on the lower leaf surfaces. Each rust species is specific to a certain host genus or species and cannot spread to unrelated plants. Moderate infections will not harm plants, but can make plants unattractive. Heavily infected leaves may curl, wither and drop prematurely. Severely infected plants may be stunted. Rusts spread primarily via windblown spores.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.

Woody Ornamentals-Deciduous-Tree

Ash (Fraxinus)

  • Ash Yellows/Lilac Witches Broom (Candidatus Phytoplasma faxini)
    Ash yellows is a chronic, systemic disease of ash trees caused by a bacteria-like organism (Phytoplasma). The organism that causes ash yellows also causes a disease called lilac witches’-broom. The ash yellows phytoplasma is thought to be spread primarily through the feeding activity of leafhopper insects.
  • Ash-Lilac Borer (Clearwing Moth) (Podosesia syringae)
    Larvae are creamy white grubs with small dark heads and small prolegs on the abdomen with hook-like crochets at the tip.
  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Scab (Venturia inaequalis)
    Scab lesions (diseased areas) are often first noticed on leaves, where they most commonly occur on the upper leaf surface. Fruits are also very susceptible to infection. Lesions on both leaves and fruits are roughly circular with feathery edges, and have an olive green to black color. They can be as small as the size of a pinhead or as large a 1/2 inch in diameter. When the disease is severe, lesions can merge and cover a large portion of the leaf or fruit surface. Defoliation of the tree often follows.
  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.

Birch (Betula)

  • Animal damage ()
    Animals that do the most damage to herbaceous plants include: deer, rabbits and woodchucks. Deer damage is distinctive because deer only have teeth on their lower jaws, so when they bite down, they must tear the plant to pull off leaves. Thus, deer damage to plants is rough or shredded-looking. It may also be several feet off of the ground. Plus, if a large amount of plant material is damaged overnight, you should suspect deer. Rabbit damage looks like someone used a pruner to cut the plant off at a clean, 45-degree angle. Woodchucks will mow down plants, or sometimes just nibble on succulent material. They are diurnal, so keep on the lookout.
  • Armillaria root rot (Armillaria species)
    Also known as shoestring root rot, this is an often lethal disease of woody plant roots and lower stems. It can affect almost any conifer or hardwood species, from seedling to maturity. Trees and shrubs stressed due to drought or defoliation are more susceptible. The fungi produce tough, cord-like strands called “rhizomorphs” that grow from decaying stumps and roots through the soil. Infection of other trees or shrubs can result from penetration of intact roots by rhizomorphs. In late summer or early fall, honey-colored mushrooms of Armillaria fungi develop near the bases of colonized plants and produce spores that are distributed by wind. Infection also can occur after these spores germinate in wounds on stems or roots. Above-ground symptoms include slow growth, yellowing and dwarfing of foliage, and thin crowns. Dieback of twigs and branches also may occur. Symptoms may develop slowly and intensify over many years or kill their host rapidly. Bark on lower stems or roots may be killed and crack, with flow of resin common on conifers. Thin white mats of fungus tissue called “mycelial fans” may be present within and beneath killed bark. Stem and root wood decayed by Armillaria fungi is often water-soaked, creamy to yellow in color, and spongy or stringy in texture. Rhizomorphs are commonly seen on or beneath the bark and growing from decayed stumps and roots.
  • Armored scale (Diaspididae family)
    Armored scales are oval, somewhat elongate (think oyster shell), small (1/20-1/8") insects that secrete a hard, waxy cover. During the adult stage, no body parts are visible except the cover. Eggs are laid under the cover and hatch into crawlers, which can move around and are susceptible to sprays and oils.
  • Birch canker (Nectria (Neonectria) galligena)
    Canker lesions first appear as small dark depressed areas on young, smooth barked stems, often killing twigs by girdling. Most cankers are centered on small branch stubs or their remains. Diseased trees usually have more than one canker. This disease is among the most important stem diseases on birch.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Girdling ()
    Decline and dieback caused by girdling, either by roots or man-made objects, usually affect mature trees moreso than young ones. Symptoms may include: thinning crown, leaf scorch, sparse foliage, leaves in tufts, branch dieback, early fall color, and leaf drop.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Nectria canker (Nectria (Neonectria))
    Nectria canker is characterized by the production of sore-like wounds (cankers) that form on twigs, branches, and trunks. Cankers can form at leaf scars and wherever injuries occur. Injuries can be caused by pruning (particularly improper pruning), frost, hail, cracking from heavy snow or ice, sunscald, insects, or mammals. Cankers appear first as slightly sunken areas on the bark, but can grow for years, becoming target-shaped or elongated. Small branches girdled by cankers can wilt suddenly, fail to leaf out, and die.
  • Planting Too Deeply ()
    Trees planted too deeply in the soil exhibit a gradual decline in their growth and development. Deep planting acts as a primary stress factor and can lead to stem girdling roots which will eventually choke the trunk. It can also make trees more susceptible to disease and insect pests, and frost cracks; can cause roots to grow up toward the surface where they will have to compete for nutrients and water; and can activate suckering shoots or adventitious roots that grow from the underground part of the trunk. If you cannot see the root flare of your woody plant, then it is planted too deeply.
  • Root rot (woody plants) (Phytophthora species (W))
    Gardeners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggestareardenersadners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggesting a nutrient deficiency. Examination of the roots of these plants reveals tissue that is soft and brown.
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • Sunscald ()
    Often the first symptom of sunscald is the reddish-brown discoloration of bark. Then, the bark shrinks, appearing sunken, splits and peels back in chunky patches exposing sapwood underneath. Often cankers develop. Severe sunscald may cause the entire trunk to be girdled, or only individual branches. Look for sunscald on the south, southwest or west side of trunks or branches. It most commonly affects trees suffering from water stress or young trees with thin bark. Newly planted or transplanted are most susceptible and container-grown plants are more likely to get sunscald than field-grown ones. Species particularly prone to sunscald include: Liriodendron, Acer, Tilia, Prunus, Pyrus, Malus, Juglans, and Ulmus.
  • Yellow-necked caterpillar (Datana ministra)
    Mature larvae are black except for a yellow orange neck and several yellow lines along the length of the body.

Buckeye (Aesculus)

  • Animal damage ()
    Animals that do the most damage to herbaceous plants include: deer, rabbits and woodchucks. Deer damage is distinctive because deer only have teeth on their lower jaws, so when they bite down, they must tear the plant to pull off leaves. Thus, deer damage to plants is rough or shredded-looking. It may also be several feet off of the ground. Plus, if a large amount of plant material is damaged overnight, you should suspect deer. Rabbit damage looks like someone used a pruner to cut the plant off at a clean, 45-degree angle. Woodchucks will mow down plants, or sometimes just nibble on succulent material. They are diurnal, so keep on the lookout.
  • Armillaria root rot (Armillaria species)
    Also known as shoestring root rot, this is an often lethal disease of woody plant roots and lower stems. It can affect almost any conifer or hardwood species, from seedling to maturity. Trees and shrubs stressed due to drought or defoliation are more susceptible. The fungi produce tough, cord-like strands called “rhizomorphs” that grow from decaying stumps and roots through the soil. Infection of other trees or shrubs can result from penetration of intact roots by rhizomorphs. In late summer or early fall, honey-colored mushrooms of Armillaria fungi develop near the bases of colonized plants and produce spores that are distributed by wind. Infection also can occur after these spores germinate in wounds on stems or roots. Above-ground symptoms include slow growth, yellowing and dwarfing of foliage, and thin crowns. Dieback of twigs and branches also may occur. Symptoms may develop slowly and intensify over many years or kill their host rapidly. Bark on lower stems or roots may be killed and crack, with flow of resin common on conifers. Thin white mats of fungus tissue called “mycelial fans” may be present within and beneath killed bark. Stem and root wood decayed by Armillaria fungi is often water-soaked, creamy to yellow in color, and spongy or stringy in texture. Rhizomorphs are commonly seen on or beneath the bark and growing from decayed stumps and roots.
  • Armored scale (Diaspididae family)
    Armored scales are oval, somewhat elongate (think oyster shell), small (1/20-1/8") insects that secrete a hard, waxy cover. During the adult stage, no body parts are visible except the cover. Eggs are laid under the cover and hatch into crawlers, which can move around and are susceptible to sprays and oils.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Girdling ()
    Decline and dieback caused by girdling, either by roots or man-made objects, usually affect mature trees moreso than young ones. Symptoms may include: thinning crown, leaf scorch, sparse foliage, leaves in tufts, branch dieback, early fall color, and leaf drop.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Planting Too Deeply ()
    Trees planted too deeply in the soil exhibit a gradual decline in their growth and development. Deep planting acts as a primary stress factor and can lead to stem girdling roots which will eventually choke the trunk. It can also make trees more susceptible to disease and insect pests, and frost cracks; can cause roots to grow up toward the surface where they will have to compete for nutrients and water; and can activate suckering shoots or adventitious roots that grow from the underground part of the trunk. If you cannot see the root flare of your woody plant, then it is planted too deeply.
  • Root rot (Fusarium species (W))
    Symptoms include stunting, chlorosis, root necrosis and death of woody plants. Symptoms are dependent on cultural practices and the local environment.
  • Root rot (woody plants) (Phytophthora species (W))
    Gardeners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggestareardenersadners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggesting a nutrient deficiency. Examination of the roots of these plants reveals tissue that is soft and brown.
  • Root rot (woody plants) (Pythium species (W))
    Gardeners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggesting a nutrient deficiency. Examination of the roots of these plants reveals tissue that is soft and brown.
  • Root rot (woody plants) (Rhizoctonia species (W))
    Symptoms on the above ground parts of larger plants include necrotic spots and blotches on the leaves, shoot blight and dieback.
  • Root rot (woody plants) (Thielaviopsis species (W))
    Uncommonly damages woody plants in the landscape. Symptoms include stunting, sparse foliage, poor foliar color and die back after the death of fibrous roots
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sunscald ()
    Often the first symptom of sunscald is the reddish-brown discoloration of bark. Then, the bark shrinks, appearing sunken, splits and peels back in chunky patches exposing sapwood underneath. Often cankers develop. Severe sunscald may cause the entire trunk to be girdled, or only individual branches. Look for sunscald on the south, southwest or west side of trunks or branches. It most commonly affects trees suffering from water stress or young trees with thin bark. Newly planted or transplanted are most susceptible and container-grown plants are more likely to get sunscald than field-grown ones. Species particularly prone to sunscald include: Liriodendron, Acer, Tilia, Prunus, Pyrus, Malus, Juglans, and Ulmus.
  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.

Catalpa (Catalpa)

  • Armillaria root rot (Armillaria species)
    Also known as shoestring root rot, this is an often lethal disease of woody plant roots and lower stems. It can affect almost any conifer or hardwood species, from seedling to maturity. Trees and shrubs stressed due to drought or defoliation are more susceptible. The fungi produce tough, cord-like strands called “rhizomorphs” that grow from decaying stumps and roots through the soil. Infection of other trees or shrubs can result from penetration of intact roots by rhizomorphs. In late summer or early fall, honey-colored mushrooms of Armillaria fungi develop near the bases of colonized plants and produce spores that are distributed by wind. Infection also can occur after these spores germinate in wounds on stems or roots. Above-ground symptoms include slow growth, yellowing and dwarfing of foliage, and thin crowns. Dieback of twigs and branches also may occur. Symptoms may develop slowly and intensify over many years or kill their host rapidly. Bark on lower stems or roots may be killed and crack, with flow of resin common on conifers. Thin white mats of fungus tissue called “mycelial fans” may be present within and beneath killed bark. Stem and root wood decayed by Armillaria fungi is often water-soaked, creamy to yellow in color, and spongy or stringy in texture. Rhizomorphs are commonly seen on or beneath the bark and growing from decayed stumps and roots.
  • Armored scale (Diaspididae family)
    Armored scales are oval, somewhat elongate (think oyster shell), small (1/20-1/8") insects that secrete a hard, waxy cover. During the adult stage, no body parts are visible except the cover. Eggs are laid under the cover and hatch into crawlers, which can move around and are susceptible to sprays and oils.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Girdling ()
    Decline and dieback caused by girdling, either by roots or man-made objects, usually affect mature trees moreso than young ones. Symptoms may include: thinning crown, leaf scorch, sparse foliage, leaves in tufts, branch dieback, early fall color, and leaf drop.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Nectria canker (Nectria (Neonectria))
    Nectria canker is characterized by the production of sore-like wounds (cankers) that form on twigs, branches, and trunks. Cankers can form at leaf scars and wherever injuries occur. Injuries can be caused by pruning (particularly improper pruning), frost, hail, cracking from heavy snow or ice, sunscald, insects, or mammals. Cankers appear first as slightly sunken areas on the bark, but can grow for years, becoming target-shaped or elongated. Small branches girdled by cankers can wilt suddenly, fail to leaf out, and die.
  • Overwatering ()
    Overwatering, whether acute or chronic, is usually a death sentence for plants, especially when accompanied with poor drainage. Waterlogged soils limit oxygen uptake by plant roots, which in turn affects the plant's metabolism, nutrient uptake, water absorption and photosynthesis. Symptoms vary from slow growth to plant death and can include: leaf necrosis, dieback, root discoloration, soil blackening, foul odors, slow growth, thinning canopy and chlorosis. Overwatered conifer symptoms are similar, except they can also exhibit needle drop. Overwatering is common in irrigated landscapes, plantings at the bottoms of slopes and in poorly drained containers.
  • Planting Too Deeply ()
    Trees planted too deeply in the soil exhibit a gradual decline in their growth and development. Deep planting acts as a primary stress factor and can lead to stem girdling roots which will eventually choke the trunk. It can also make trees more susceptible to disease and insect pests, and frost cracks; can cause roots to grow up toward the surface where they will have to compete for nutrients and water; and can activate suckering shoots or adventitious roots that grow from the underground part of the trunk. If you cannot see the root flare of your woody plant, then it is planted too deeply.
  • Root rot (woody plants) (Thielaviopsis species (W))
    Uncommonly damages woody plants in the landscape. Symptoms include stunting, sparse foliage, poor foliar color and die back after the death of fibrous roots
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • Sunscald ()
    Often the first symptom of sunscald is the reddish-brown discoloration of bark. Then, the bark shrinks, appearing sunken, splits and peels back in chunky patches exposing sapwood underneath. Often cankers develop. Severe sunscald may cause the entire trunk to be girdled, or only individual branches. Look for sunscald on the south, southwest or west side of trunks or branches. It most commonly affects trees suffering from water stress or young trees with thin bark. Newly planted or transplanted are most susceptible and container-grown plants are more likely to get sunscald than field-grown ones. Species particularly prone to sunscald include: Liriodendron, Acer, Tilia, Prunus, Pyrus, Malus, Juglans, and Ulmus.
  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.

Coffeetree (Gymnocladus)

  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.

Crabapple (Malus)

  • Cedar-rosaceous rusts (Cedar-apple, cedar-hawthorn, cedar-quince rust on deciduous hosts) (Gymnosporangium (Deciduous))
    On junipers, the cedar-rosaceous rust fungus causes formation of irregularly-shaped brown galls (roughly 1/2 to junipers, the cedar-rosaceous rust fungus causes formation of irregularly-shaped brown galls (roughly 1/2 to two inches in diameter). During moist periods in spring, these galls produce a distinctive orange, gelatinous slime. Symptoms on rosaceous hosts appear in late May as circular, yellow-orange areas on leaves. The undersurfaces of these diseased areas often have a fringed appearance.
  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Scab (Venturia inaequalis)
    Scab lesions (diseased areas) are often first noticed on leaves, where they most commonly occur on the upper leaf surface. Fruits are also very susceptible to infection. Lesions on both leaves and fruits are roughly circular with feathery edges, and have an olive green to black color. They can be as small as the size of a pinhead or as large a 1/2 inch in diameter. When the disease is severe, lesions can merge and cover a large portion of the leaf or fruit surface. Defoliation of the tree often follows.
  • Yellow-necked caterpillar (Datana ministra)
    Mature larvae are black except for a yellow orange neck and several yellow lines along the length of the body.

Elm (Ulmus)

  • Dutch elm disease (Ophiostoma novo-ulmi)
    Wilting leaves, often on a single branch, are the first symptoms of Dutch elm disease. Yellowing of leaves and leaf drop follow. Trees may quickly lose all of their leaves, or trees may survive several years with an infection localized in a single branch. Infected branches often have brown streaks under the bark that follow the wood grain.
  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.
  • Yellow-necked caterpillar (Datana ministra)
    Mature larvae are black except for a yellow orange neck and several yellow lines along the length of the body.

Filbert (Corylus)

  • Armillaria root rot (Armillaria species)
    Also known as shoestring root rot, this is an often lethal disease of woody plant roots and lower stems. It can affect almost any conifer or hardwood species, from seedling to maturity. Trees and shrubs stressed due to drought or defoliation are more susceptible. The fungi produce tough, cord-like strands called “rhizomorphs” that grow from decaying stumps and roots through the soil. Infection of other trees or shrubs can result from penetration of intact roots by rhizomorphs. In late summer or early fall, honey-colored mushrooms of Armillaria fungi develop near the bases of colonized plants and produce spores that are distributed by wind. Infection also can occur after these spores germinate in wounds on stems or roots. Above-ground symptoms include slow growth, yellowing and dwarfing of foliage, and thin crowns. Dieback of twigs and branches also may occur. Symptoms may develop slowly and intensify over many years or kill their host rapidly. Bark on lower stems or roots may be killed and crack, with flow of resin common on conifers. Thin white mats of fungus tissue called “mycelial fans” may be present within and beneath killed bark. Stem and root wood decayed by Armillaria fungi is often water-soaked, creamy to yellow in color, and spongy or stringy in texture. Rhizomorphs are commonly seen on or beneath the bark and growing from decayed stumps and roots.
  • Birch canker (Nectria (Neonectria) galligena)
    Canker lesions first appear as small dark depressed areas on young, smooth barked stems, often killing twigs by girdling. Most cankers are centered on small branch stubs or their remains. Diseased trees usually have more than one canker. This disease is among the most important stem diseases on birch.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Girdling ()
    Decline and dieback caused by girdling, either by roots or man-made objects, usually affect mature trees moreso than young ones. Symptoms may include: thinning crown, leaf scorch, sparse foliage, leaves in tufts, branch dieback, early fall color, and leaf drop.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Overwatering ()
    Overwatering, whether acute or chronic, is usually a death sentence for plants, especially when accompanied with poor drainage. Waterlogged soils limit oxygen uptake by plant roots, which in turn affects the plant's metabolism, nutrient uptake, water absorption and photosynthesis. Symptoms vary from slow growth to plant death and can include: leaf necrosis, dieback, root discoloration, soil blackening, foul odors, slow growth, thinning canopy and chlorosis. Overwatered conifer symptoms are similar, except they can also exhibit needle drop. Overwatering is common in irrigated landscapes, plantings at the bottoms of slopes and in poorly drained containers.
  • Planting Too Deeply ()
    Trees planted too deeply in the soil exhibit a gradual decline in their growth and development. Deep planting acts as a primary stress factor and can lead to stem girdling roots which will eventually choke the trunk. It can also make trees more susceptible to disease and insect pests, and frost cracks; can cause roots to grow up toward the surface where they will have to compete for nutrients and water; and can activate suckering shoots or adventitious roots that grow from the underground part of the trunk. If you cannot see the root flare of your woody plant, then it is planted too deeply.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • Sunscald ()
    Often the first symptom of sunscald is the reddish-brown discoloration of bark. Then, the bark shrinks, appearing sunken, splits and peels back in chunky patches exposing sapwood underneath. Often cankers develop. Severe sunscald may cause the entire trunk to be girdled, or only individual branches. Look for sunscald on the south, southwest or west side of trunks or branches. It most commonly affects trees suffering from water stress or young trees with thin bark. Newly planted or transplanted are most susceptible and container-grown plants are more likely to get sunscald than field-grown ones. Species particularly prone to sunscald include: Liriodendron, Acer, Tilia, Prunus, Pyrus, Malus, Juglans, and Ulmus.

Hackberry (Celtis)

  • Armillaria root rot (Armillaria species)
    Also known as shoestring root rot, this is an often lethal disease of woody plant roots and lower stems. It can affect almost any conifer or hardwood species, from seedling to maturity. Trees and shrubs stressed due to drought or defoliation are more susceptible. The fungi produce tough, cord-like strands called “rhizomorphs” that grow from decaying stumps and roots through the soil. Infection of other trees or shrubs can result from penetration of intact roots by rhizomorphs. In late summer or early fall, honey-colored mushrooms of Armillaria fungi develop near the bases of colonized plants and produce spores that are distributed by wind. Infection also can occur after these spores germinate in wounds on stems or roots. Above-ground symptoms include slow growth, yellowing and dwarfing of foliage, and thin crowns. Dieback of twigs and branches also may occur. Symptoms may develop slowly and intensify over many years or kill their host rapidly. Bark on lower stems or roots may be killed and crack, with flow of resin common on conifers. Thin white mats of fungus tissue called “mycelial fans” may be present within and beneath killed bark. Stem and root wood decayed by Armillaria fungi is often water-soaked, creamy to yellow in color, and spongy or stringy in texture. Rhizomorphs are commonly seen on or beneath the bark and growing from decayed stumps and roots.
  • Armored scale (Diaspididae family)
    Armored scales are oval, somewhat elongate (think oyster shell), small (1/20-1/8") insects that secrete a hard, waxy cover. During the adult stage, no body parts are visible except the cover. Eggs are laid under the cover and hatch into crawlers, which can move around and are susceptible to sprays and oils.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Downy mildew (Woody plants) (Peronosporaceae family)
  • Girdling ()
    Decline and dieback caused by girdling, either by roots or man-made objects, usually affect mature trees moreso than young ones. Symptoms may include: thinning crown, leaf scorch, sparse foliage, leaves in tufts, branch dieback, early fall color, and leaf drop.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Nectria canker (Nectria (Neonectria))
    Nectria canker is characterized by the production of sore-like wounds (cankers) that form on twigs, branches, and trunks. Cankers can form at leaf scars and wherever injuries occur. Injuries can be caused by pruning (particularly improper pruning), frost, hail, cracking from heavy snow or ice, sunscald, insects, or mammals. Cankers appear first as slightly sunken areas on the bark, but can grow for years, becoming target-shaped or elongated. Small branches girdled by cankers can wilt suddenly, fail to leaf out, and die.
  • Planting Too Deeply ()
    Trees planted too deeply in the soil exhibit a gradual decline in their growth and development. Deep planting acts as a primary stress factor and can lead to stem girdling roots which will eventually choke the trunk. It can also make trees more susceptible to disease and insect pests, and frost cracks; can cause roots to grow up toward the surface where they will have to compete for nutrients and water; and can activate suckering shoots or adventitious roots that grow from the underground part of the trunk. If you cannot see the root flare of your woody plant, then it is planted too deeply.
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sunscald ()
    Often the first symptom of sunscald is the reddish-brown discoloration of bark. Then, the bark shrinks, appearing sunken, splits and peels back in chunky patches exposing sapwood underneath. Often cankers develop. Severe sunscald may cause the entire trunk to be girdled, or only individual branches. Look for sunscald on the south, southwest or west side of trunks or branches. It most commonly affects trees suffering from water stress or young trees with thin bark. Newly planted or transplanted are most susceptible and container-grown plants are more likely to get sunscald than field-grown ones. Species particularly prone to sunscald include: Liriodendron, Acer, Tilia, Prunus, Pyrus, Malus, Juglans, and Ulmus.

Hawthorn (Crataegus)

  • Armillaria root rot (Armillaria species)
    Also known as shoestring root rot, this is an often lethal disease of woody plant roots and lower stems. It can affect almost any conifer or hardwood species, from seedling to maturity. Trees and shrubs stressed due to drought or defoliation are more susceptible. The fungi produce tough, cord-like strands called “rhizomorphs” that grow from decaying stumps and roots through the soil. Infection of other trees or shrubs can result from penetration of intact roots by rhizomorphs. In late summer or early fall, honey-colored mushrooms of Armillaria fungi develop near the bases of colonized plants and produce spores that are distributed by wind. Infection also can occur after these spores germinate in wounds on stems or roots. Above-ground symptoms include slow growth, yellowing and dwarfing of foliage, and thin crowns. Dieback of twigs and branches also may occur. Symptoms may develop slowly and intensify over many years or kill their host rapidly. Bark on lower stems or roots may be killed and crack, with flow of resin common on conifers. Thin white mats of fungus tissue called “mycelial fans” may be present within and beneath killed bark. Stem and root wood decayed by Armillaria fungi is often water-soaked, creamy to yellow in color, and spongy or stringy in texture. Rhizomorphs are commonly seen on or beneath the bark and growing from decayed stumps and roots.
  • Armored scale (Diaspididae family)
    Armored scales are oval, somewhat elongate (think oyster shell), small (1/20-1/8") insects that secrete a hard, waxy cover. During the adult stage, no body parts are visible except the cover. Eggs are laid under the cover and hatch into crawlers, which can move around and are susceptible to sprays and oils.
  • Birch canker (Nectria (Neonectria) galligena)
    Canker lesions first appear as small dark depressed areas on young, smooth barked stems, often killing twigs by girdling. Most cankers are centered on small branch stubs or their remains. Diseased trees usually have more than one canker. This disease is among the most important stem diseases on birch.
  • Cedar-rosaceous rusts (Cedar-apple, cedar-hawthorn, cedar-quince rust on deciduous hosts) (Gymnosporangium (Deciduous))
    On junipers, the cedar-rosaceous rust fungus causes formation of irregularly-shaped brown galls (roughly 1/2 to junipers, the cedar-rosaceous rust fungus causes formation of irregularly-shaped brown galls (roughly 1/2 to two inches in diameter). During moist periods in spring, these galls produce a distinctive orange, gelatinous slime. Symptoms on rosaceous hosts appear in late May as circular, yellow-orange areas on leaves. The undersurfaces of these diseased areas often have a fringed appearance.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Cucumber beetle (Spotted/Striped) (Chrysomelidae family (CB))
    Larvae are pale-colored and wormlike with brown heads. Adult spotted cucumber beetles are about 1/4" long, with shiny black heads and greenish-yellow with 12 black spots on their backs. Adult striped cucumber beetles are about 1/4" long, with shiny black heads and are yellowish-orange with 3 black stripes. There may be 1-2 generations of each type of cucumber beetle per year.
  • Cytospora canker (Cytospora species)
    A stem and branch disorder affecting many different types of conifers. In Wisconsin, Colorado Blue Spruce is the main species that is affected.
  • Girdling ()
    Decline and dieback caused by girdling, either by roots or man-made objects, usually affect mature trees moreso than young ones. Symptoms may include: thinning crown, leaf scorch, sparse foliage, leaves in tufts, branch dieback, early fall color, and leaf drop.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Planting Too Deeply ()
    Trees planted too deeply in the soil exhibit a gradual decline in their growth and development. Deep planting acts as a primary stress factor and can lead to stem girdling roots which will eventually choke the trunk. It can also make trees more susceptible to disease and insect pests, and frost cracks; can cause roots to grow up toward the surface where they will have to compete for nutrients and water; and can activate suckering shoots or adventitious roots that grow from the underground part of the trunk. If you cannot see the root flare of your woody plant, then it is planted too deeply.
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • Sunscald ()
    Often the first symptom of sunscald is the reddish-brown discoloration of bark. Then, the bark shrinks, appearing sunken, splits and peels back in chunky patches exposing sapwood underneath. Often cankers develop. Severe sunscald may cause the entire trunk to be girdled, or only individual branches. Look for sunscald on the south, southwest or west side of trunks or branches. It most commonly affects trees suffering from water stress or young trees with thin bark. Newly planted or transplanted are most susceptible and container-grown plants are more likely to get sunscald than field-grown ones. Species particularly prone to sunscald include: Liriodendron, Acer, Tilia, Prunus, Pyrus, Malus, Juglans, and Ulmus.
  • Yellow-necked caterpillar (Datana ministra)
    Mature larvae are black except for a yellow orange neck and several yellow lines along the length of the body.

Hickory (Carya)

  • Animal damage ()
    Animals that do the most damage to herbaceous plants include: deer, rabbits and woodchucks. Deer damage is distinctive because deer only have teeth on their lower jaws, so when they bite down, they must tear the plant to pull off leaves. Thus, deer damage to plants is rough or shredded-looking. It may also be several feet off of the ground. Plus, if a large amount of plant material is damaged overnight, you should suspect deer. Rabbit damage looks like someone used a pruner to cut the plant off at a clean, 45-degree angle. Woodchucks will mow down plants, or sometimes just nibble on succulent material. They are diurnal, so keep on the lookout.
  • Armillaria root rot (Armillaria species)
    Also known as shoestring root rot, this is an often lethal disease of woody plant roots and lower stems. It can affect almost any conifer or hardwood species, from seedling to maturity. Trees and shrubs stressed due to drought or defoliation are more susceptible. The fungi produce tough, cord-like strands called “rhizomorphs” that grow from decaying stumps and roots through the soil. Infection of other trees or shrubs can result from penetration of intact roots by rhizomorphs. In late summer or early fall, honey-colored mushrooms of Armillaria fungi develop near the bases of colonized plants and produce spores that are distributed by wind. Infection also can occur after these spores germinate in wounds on stems or roots. Above-ground symptoms include slow growth, yellowing and dwarfing of foliage, and thin crowns. Dieback of twigs and branches also may occur. Symptoms may develop slowly and intensify over many years or kill their host rapidly. Bark on lower stems or roots may be killed and crack, with flow of resin common on conifers. Thin white mats of fungus tissue called “mycelial fans” may be present within and beneath killed bark. Stem and root wood decayed by Armillaria fungi is often water-soaked, creamy to yellow in color, and spongy or stringy in texture. Rhizomorphs are commonly seen on or beneath the bark and growing from decayed stumps and roots.
  • Armored scale (Diaspididae family)
    Armored scales are oval, somewhat elongate (think oyster shell), small (1/20-1/8") insects that secrete a hard, waxy cover. During the adult stage, no body parts are visible except the cover. Eggs are laid under the cover and hatch into crawlers, which can move around and are susceptible to sprays and oils.
  • Birch canker (Nectria (Neonectria) galligena)
    Canker lesions first appear as small dark depressed areas on young, smooth barked stems, often killing twigs by girdling. Most cankers are centered on small branch stubs or their remains. Diseased trees usually have more than one canker. This disease is among the most important stem diseases on birch.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Girdling ()
    Decline and dieback caused by girdling, either by roots or man-made objects, usually affect mature trees moreso than young ones. Symptoms may include: thinning crown, leaf scorch, sparse foliage, leaves in tufts, branch dieback, early fall color, and leaf drop.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Nectria canker (Nectria (Neonectria))
    Nectria canker is characterized by the production of sore-like wounds (cankers) that form on twigs, branches, and trunks. Cankers can form at leaf scars and wherever injuries occur. Injuries can be caused by pruning (particularly improper pruning), frost, hail, cracking from heavy snow or ice, sunscald, insects, or mammals. Cankers appear first as slightly sunken areas on the bark, but can grow for years, becoming target-shaped or elongated. Small branches girdled by cankers can wilt suddenly, fail to leaf out, and die.
  • Planting Too Deeply ()
    Trees planted too deeply in the soil exhibit a gradual decline in their growth and development. Deep planting acts as a primary stress factor and can lead to stem girdling roots which will eventually choke the trunk. It can also make trees more susceptible to disease and insect pests, and frost cracks; can cause roots to grow up toward the surface where they will have to compete for nutrients and water; and can activate suckering shoots or adventitious roots that grow from the underground part of the trunk. If you cannot see the root flare of your woody plant, then it is planted too deeply.
  • Root rot (woody plants) (Cylindrocladium species)
    Root infections are characterized by many dark brown to black lesions often with longitudinal cracks. Severe root disease leads to stunting, wilting, yellowing and death. Stem infections of both conifers and broadleaves arise at the leaf bases and may girdle small stems. Diseased conifer needles turn yellow or red-brown. Dark lesions form in the leaves of broadleaf plants. Leaf blight leads to defoliation.
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • Sunscald ()
    Often the first symptom of sunscald is the reddish-brown discoloration of bark. Then, the bark shrinks, appearing sunken, splits and peels back in chunky patches exposing sapwood underneath. Often cankers develop. Severe sunscald may cause the entire trunk to be girdled, or only individual branches. Look for sunscald on the south, southwest or west side of trunks or branches. It most commonly affects trees suffering from water stress or young trees with thin bark. Newly planted or transplanted are most susceptible and container-grown plants are more likely to get sunscald than field-grown ones. Species particularly prone to sunscald include: Liriodendron, Acer, Tilia, Prunus, Pyrus, Malus, Juglans, and Ulmus.
  • Yellow-necked caterpillar (Datana ministra)
    Mature larvae are black except for a yellow orange neck and several yellow lines along the length of the body.

Honeylocust (Gleditsia )

  • Nectria canker (Nectria (Neonectria))
    Nectria canker is characterized by the production of sore-like wounds (cankers) that form on twigs, branches, and trunks. Cankers can form at leaf scars and wherever injuries occur. Injuries can be caused by pruning (particularly improper pruning), frost, hail, cracking from heavy snow or ice, sunscald, insects, or mammals. Cankers appear first as slightly sunken areas on the bark, but can grow for years, becoming target-shaped or elongated. Small branches girdled by cankers can wilt suddenly, fail to leaf out, and die.

Linden (Tilia)

  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Linden borer (Saperda vestia)
    Primary color is olive green to yellow brown because of hairs covering the dark colored body. Most have dark spots on each wing cover, two above the middle of the wing and one below.

Locust (Robinia)

  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.

Magnolia (Magnolia)

  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.

Maple (Acer)

  • Animal damage ()
    Animals that do the most damage to herbaceous plants include: deer, rabbits and woodchucks. Deer damage is distinctive because deer only have teeth on their lower jaws, so when they bite down, they must tear the plant to pull off leaves. Thus, deer damage to plants is rough or shredded-looking. It may also be several feet off of the ground. Plus, if a large amount of plant material is damaged overnight, you should suspect deer. Rabbit damage looks like someone used a pruner to cut the plant off at a clean, 45-degree angle. Woodchucks will mow down plants, or sometimes just nibble on succulent material. They are diurnal, so keep on the lookout.
  • Armillaria root rot (Armillaria species)
    Also known as shoestring root rot, this is an often lethal disease of woody plant roots and lower stems. It can affect almost any conifer or hardwood species, from seedling to maturity. Trees and shrubs stressed due to drought or defoliation are more susceptible. The fungi produce tough, cord-like strands called “rhizomorphs” that grow from decaying stumps and roots through the soil. Infection of other trees or shrubs can result from penetration of intact roots by rhizomorphs. In late summer or early fall, honey-colored mushrooms of Armillaria fungi develop near the bases of colonized plants and produce spores that are distributed by wind. Infection also can occur after these spores germinate in wounds on stems or roots. Above-ground symptoms include slow growth, yellowing and dwarfing of foliage, and thin crowns. Dieback of twigs and branches also may occur. Symptoms may develop slowly and intensify over many years or kill their host rapidly. Bark on lower stems or roots may be killed and crack, with flow of resin common on conifers. Thin white mats of fungus tissue called “mycelial fans” may be present within and beneath killed bark. Stem and root wood decayed by Armillaria fungi is often water-soaked, creamy to yellow in color, and spongy or stringy in texture. Rhizomorphs are commonly seen on or beneath the bark and growing from decayed stumps and roots.
  • Armored scale (Diaspididae family)
    Armored scales are oval, somewhat elongate (think oyster shell), small (1/20-1/8") insects that secrete a hard, waxy cover. During the adult stage, no body parts are visible except the cover. Eggs are laid under the cover and hatch into crawlers, which can move around and are susceptible to sprays and oils.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Girdling ()
    Decline and dieback caused by girdling, either by roots or man-made objects, usually affect mature trees moreso than young ones. Symptoms may include: thinning crown, leaf scorch, sparse foliage, leaves in tufts, branch dieback, early fall color, and leaf drop.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Planting Too Deeply ()
    Trees planted too deeply in the soil exhibit a gradual decline in their growth and development. Deep planting acts as a primary stress factor and can lead to stem girdling roots which will eventually choke the trunk. It can also make trees more susceptible to disease and insect pests, and frost cracks; can cause roots to grow up toward the surface where they will have to compete for nutrients and water; and can activate suckering shoots or adventitious roots that grow from the underground part of the trunk. If you cannot see the root flare of your woody plant, then it is planted too deeply.
  • Root rot (woody plants) (Phytophthora species (W))
    Gardeners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggestareardenersadners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggesting a nutrient deficiency. Examination of the roots of these plants reveals tissue that is soft and brown.
  • Root rot (woody plants) (Pythium species (W))
    Gardeners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggesting a nutrient deficiency. Examination of the roots of these plants reveals tissue that is soft and brown.
  • Root rot (woody plants) (Rhizoctonia species (W))
    Symptoms on the above ground parts of larger plants include necrotic spots and blotches on the leaves, shoot blight and dieback.
  • Root rot (woody plants) (Thielaviopsis species (W))
    Uncommonly damages woody plants in the landscape. Symptoms include stunting, sparse foliage, poor foliar color and die back after the death of fibrous roots
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • Sunscald ()
    Often the first symptom of sunscald is the reddish-brown discoloration of bark. Then, the bark shrinks, appearing sunken, splits and peels back in chunky patches exposing sapwood underneath. Often cankers develop. Severe sunscald may cause the entire trunk to be girdled, or only individual branches. Look for sunscald on the south, southwest or west side of trunks or branches. It most commonly affects trees suffering from water stress or young trees with thin bark. Newly planted or transplanted are most susceptible and container-grown plants are more likely to get sunscald than field-grown ones. Species particularly prone to sunscald include: Liriodendron, Acer, Tilia, Prunus, Pyrus, Malus, Juglans, and Ulmus.
  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.
  • Yellow-necked caterpillar (Datana ministra)
    Mature larvae are black except for a yellow orange neck and several yellow lines along the length of the body.

Mountain Ash (Sorbus)

  • Cedar-rosaceous rusts (Cedar-apple, cedar-hawthorn, cedar-quince rust on deciduous hosts) (Gymnosporangium (Deciduous))
    On junipers, the cedar-rosaceous rust fungus causes formation of irregularly-shaped brown galls (roughly 1/2 to junipers, the cedar-rosaceous rust fungus causes formation of irregularly-shaped brown galls (roughly 1/2 to two inches in diameter). During moist periods in spring, these galls produce a distinctive orange, gelatinous slime. Symptoms on rosaceous hosts appear in late May as circular, yellow-orange areas on leaves. The undersurfaces of these diseased areas often have a fringed appearance.

Oak (Quercus)

  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Oak wilt (Ceratocystis fagacearum)
    Initially, single branches on infected trees wilt and die. Leaves on these branches often bronze, or turn tan or dull green, starting at the tips or outer margins. Leaves may also droop, curl, or fall from the tree. Infected trees eventually die. Oak wilt can kill oaks in the red oak group in less than one month. Oaks in the white oak group usually have less severe symptoms and are rarely killed in one season.
  • Yellow-necked caterpillar (Datana ministra)
    Mature larvae are black except for a yellow orange neck and several yellow lines along the length of the body.

Plum / Cherry (Prunus)

  • Black knot (Apiosporina morbosa)
    During the first year of infection, black knot-infected trees develop greenish-brown to brown swellings on affected branches and trunks. During the second year, these swellings enlarge into the ugly, black, erupting tumors (galls) characteristic of the disease. Older gall tissue (greater than two years old) often dies and then is colonized by fungi that give the gall a whitish or pinkish color. Severe black knot infections may cause general tree decline or death if galls girdle large limbs or tree trunks.
  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.
  • Yellow-necked caterpillar (Datana ministra)
    Mature larvae are black except for a yellow orange neck and several yellow lines along the length of the body.

Redbud (Cercis)

  • Armillaria root rot (Armillaria species)
    Also known as shoestring root rot, this is an often lethal disease of woody plant roots and lower stems. It can affect almost any conifer or hardwood species, from seedling to maturity. Trees and shrubs stressed due to drought or defoliation are more susceptible. The fungi produce tough, cord-like strands called “rhizomorphs” that grow from decaying stumps and roots through the soil. Infection of other trees or shrubs can result from penetration of intact roots by rhizomorphs. In late summer or early fall, honey-colored mushrooms of Armillaria fungi develop near the bases of colonized plants and produce spores that are distributed by wind. Infection also can occur after these spores germinate in wounds on stems or roots. Above-ground symptoms include slow growth, yellowing and dwarfing of foliage, and thin crowns. Dieback of twigs and branches also may occur. Symptoms may develop slowly and intensify over many years or kill their host rapidly. Bark on lower stems or roots may be killed and crack, with flow of resin common on conifers. Thin white mats of fungus tissue called “mycelial fans” may be present within and beneath killed bark. Stem and root wood decayed by Armillaria fungi is often water-soaked, creamy to yellow in color, and spongy or stringy in texture. Rhizomorphs are commonly seen on or beneath the bark and growing from decayed stumps and roots.
  • Armored scale (Diaspididae family)
    Armored scales are oval, somewhat elongate (think oyster shell), small (1/20-1/8") insects that secrete a hard, waxy cover. During the adult stage, no body parts are visible except the cover. Eggs are laid under the cover and hatch into crawlers, which can move around and are susceptible to sprays and oils.
  • Birch canker (Nectria (Neonectria) galligena)
    Canker lesions first appear as small dark depressed areas on young, smooth barked stems, often killing twigs by girdling. Most cankers are centered on small branch stubs or their remains. Diseased trees usually have more than one canker. This disease is among the most important stem diseases on birch.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Downy mildew (Woody plants) (Peronosporaceae family)
  • Girdling ()
    Decline and dieback caused by girdling, either by roots or man-made objects, usually affect mature trees moreso than young ones. Symptoms may include: thinning crown, leaf scorch, sparse foliage, leaves in tufts, branch dieback, early fall color, and leaf drop.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.
  • Planting Too Deeply ()
    Trees planted too deeply in the soil exhibit a gradual decline in their growth and development. Deep planting acts as a primary stress factor and can lead to stem girdling roots which will eventually choke the trunk. It can also make trees more susceptible to disease and insect pests, and frost cracks; can cause roots to grow up toward the surface where they will have to compete for nutrients and water; and can activate suckering shoots or adventitious roots that grow from the underground part of the trunk. If you cannot see the root flare of your woody plant, then it is planted too deeply.
  • Root rot (woody plants) (Cylindrocladium species)
    Root infections are characterized by many dark brown to black lesions often with longitudinal cracks. Severe root disease leads to stunting, wilting, yellowing and death. Stem infections of both conifers and broadleaves arise at the leaf bases and may girdle small stems. Diseased conifer needles turn yellow or red-brown. Dark lesions form in the leaves of broadleaf plants. Leaf blight leads to defoliation.
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • Sunscald ()
    Often the first symptom of sunscald is the reddish-brown discoloration of bark. Then, the bark shrinks, appearing sunken, splits and peels back in chunky patches exposing sapwood underneath. Often cankers develop. Severe sunscald may cause the entire trunk to be girdled, or only individual branches. Look for sunscald on the south, southwest or west side of trunks or branches. It most commonly affects trees suffering from water stress or young trees with thin bark. Newly planted or transplanted are most susceptible and container-grown plants are more likely to get sunscald than field-grown ones. Species particularly prone to sunscald include: Liriodendron, Acer, Tilia, Prunus, Pyrus, Malus, Juglans, and Ulmus.
  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.

Russian Olive (Elaeagnus )

  • Phomopsis canker (Phomopsis species)
    Kills seedlings/saplings and causes cankers on larger plants. Shriveled, faded foliage can be found on dead branches and small trees from midsummer to fall. Young cankers in smooth-barked branches are reddish-brown to black. An amber-brown gum is often exuded from lesions. Cankers on trunks and scaffold limbs appear as dark, depressed areas leading to splits in the bark. Within a month after infection, pimply eruptions appear on the surface. Initially grayish-tan, eruptions darken with age and eventually turn black. Usually they are abundant by the time the disease is detected but remain prominent for at least a year.
  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.

Serviceberry (Amelanchier)

  • Animal damage ()
    Animals that do the most damage to herbaceous plants include: deer, rabbits and woodchucks. Deer damage is distinctive because deer only have teeth on their lower jaws, so when they bite down, they must tear the plant to pull off leaves. Thus, deer damage to plants is rough or shredded-looking. It may also be several feet off of the ground. Plus, if a large amount of plant material is damaged overnight, you should suspect deer. Rabbit damage looks like someone used a pruner to cut the plant off at a clean, 45-degree angle. Woodchucks will mow down plants, or sometimes just nibble on succulent material. They are diurnal, so keep on the lookout.
  • Armillaria root rot (Armillaria species)
    Also known as shoestring root rot, this is an often lethal disease of woody plant roots and lower stems. It can affect almost any conifer or hardwood species, from seedling to maturity. Trees and shrubs stressed due to drought or defoliation are more susceptible. The fungi produce tough, cord-like strands called “rhizomorphs” that grow from decaying stumps and roots through the soil. Infection of other trees or shrubs can result from penetration of intact roots by rhizomorphs. In late summer or early fall, honey-colored mushrooms of Armillaria fungi develop near the bases of colonized plants and produce spores that are distributed by wind. Infection also can occur after these spores germinate in wounds on stems or roots. Above-ground symptoms include slow growth, yellowing and dwarfing of foliage, and thin crowns. Dieback of twigs and branches also may occur. Symptoms may develop slowly and intensify over many years or kill their host rapidly. Bark on lower stems or roots may be killed and crack, with flow of resin common on conifers. Thin white mats of fungus tissue called “mycelial fans” may be present within and beneath killed bark. Stem and root wood decayed by Armillaria fungi is often water-soaked, creamy to yellow in color, and spongy or stringy in texture. Rhizomorphs are commonly seen on or beneath the bark and growing from decayed stumps and roots.
  • Armored scale (Diaspididae family)
    Armored scales are oval, somewhat elongate (think oyster shell), small (1/20-1/8") insects that secrete a hard, waxy cover. During the adult stage, no body parts are visible except the cover. Eggs are laid under the cover and hatch into crawlers, which can move around and are susceptible to sprays and oils.
  • Cedar-rosaceous rusts (Cedar-apple, cedar-hawthorn, cedar-quince rust on deciduous hosts) (Gymnosporangium (Deciduous))
    On junipers, the cedar-rosaceous rust fungus causes formation of irregularly-shaped brown galls (roughly 1/2 to junipers, the cedar-rosaceous rust fungus causes formation of irregularly-shaped brown galls (roughly 1/2 to two inches in diameter). During moist periods in spring, these galls produce a distinctive orange, gelatinous slime. Symptoms on rosaceous hosts appear in late May as circular, yellow-orange areas on leaves. The undersurfaces of these diseased areas often have a fringed appearance.
  • Cold/Frost Damage ()
    Any part of a plant may be affected by cold damage. In spring, it's usually tender growth, which will appear watersoaked and may turn black. Flower buds can sustain damage during winter dormancy or during the blooming period. Plants will either have reduced numbers of blooms, and hence fruit set, or won't bloom at all. In fall, if plants aren't hardened off, they can sustain cold injury in temperatures well above those tolerated by acclimated plants. Root injury is rare unless plants are in raised beds or containers. Generally younger plants are more susceptible than mature plants. Cold injury on woody plants usually presents in the form of frost cracks in wood or bark. Mature leaves may turn red, purple, brown or black and may or may not fall off the tree or shrub.
  • Girdling ()
    Decline and dieback caused by girdling, either by roots or man-made objects, usually affect mature trees moreso than young ones. Symptoms may include: thinning crown, leaf scorch, sparse foliage, leaves in tufts, branch dieback, early fall color, and leaf drop.
  • Herbicide Damage ()
    Herbicides can damage any type of plant and injury usually happens as a result of drift, careless application or evaporation during hot weather. Symptoms of herbicide injury may include: twisted plant stems; stem fasciation; narrow, curling or leathery leaves; or excessive callus formation on roots and stems along with secondary root growth. At extremely low application rates, broadleaf herbicides such as 2,4-D, MCPP or dicamba usually will not kill plants, although they will act as growth regulators.
  • Mealybug (Pseudococcidae family)
    Characteristically mealybugs are covered in white granular or cotton-like wax. Mealy bug bodies are always soft and the females are oval and flat with distinct segmentation often visible in the wax. Eggs are usually laid in a white cottony material underneath the female. Widespread in greenhouses and indoor plants; not an outdoor problem. Depending on temperature, one generation can develop every 1-3 months.
  • Nitrogen Overapplication ()
    Excessive nitrogen (N) application produces 'too rapid' growth which results in softness of tissue and general plant weakness. While N spurs green growth, flowers and seed formation will be greatly reduced. Plants with excess N are more susceptible to disease and injury.
  • Planting Too Deeply ()
    Trees planted too deeply in the soil exhibit a gradual decline in their growth and development. Deep planting acts as a primary stress factor and can lead to stem girdling roots which will eventually choke the trunk. It can also make trees more susceptible to disease and insect pests, and frost cracks; can cause roots to grow up toward the surface where they will have to compete for nutrients and water; and can activate suckering shoots or adventitious roots that grow from the underground part of the trunk. If you cannot see the root flare of your woody plant, then it is planted too deeply.
  • Root rot (Fusarium species (W))
    Symptoms include stunting, chlorosis, root necrosis and death of woody plants. Symptoms are dependent on cultural practices and the local environment.
  • Root rot (woody plants) (Phytophthora species (W))
    Gardeners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggestareardenersadners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggesting a nutrient deficiency. Examination of the roots of these plants reveals tissue that is soft and brown.
  • Root rot (woody plants) (Pythium species (W))
    Gardeners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggesting a nutrient deficiency. Examination of the roots of these plants reveals tissue that is soft and brown.
  • Root rot (woody plants) (Rhizoctonia species (W))
    Symptoms on the above ground parts of larger plants include necrotic spots and blotches on the leaves, shoot blight and dieback.
  • Root rot (woody plants) (Thielaviopsis species (W))
    Uncommonly damages woody plants in the landscape. Symptoms include stunting, sparse foliage, poor foliar color and die back after the death of fibrous roots
  • Soft scale (Coccidae family)
    Soft scales are usually broadly oval becoming larger and more humped as eggs mature underneath the protective cover. Look for adults on twigs or small branches and immature stages on leaves or needles.
  • Soil Compaction ()
    Soil compaction is usually one of several factors that can lead to the decline of woody plants. It is a physical factor, much like drought, freezing or mechanical damage. When combined with chemical factors such as salinity, nutrient imbalances, soil acidification, herbicides or pollution and biotic factors, such as disease or insect problems, the tree will often go into slow decline. Remove any one of these factors before the plant dies or is beyond help, and the decline can be arrested and the plant may recover. Symptoms of soil compaction vary with tree species and cause, but they can include: slow growth; small, distorted, sparse, chlorotic and nutrient-deficient leaves; scorch; premature autumn color; premature leaf drop; abnormally large "distress" crops of fruit; insufficient storage of food reserves for winter; and dieback of twigs or branches. The three factors that lead to soil compaction are gravity, rain and traffic.
  • Sooty molds (Several)
    Sooty molds are dark fungi that grow on plant surfaces covered in honeydew excreted by insects with piercing/sucking mouth parts such as aphids, scale, mealybugs and whiteflies. It is generally harmless to plants, except when it is prolific, preventing light from reaching leaf surfaces, causing plants stress. This stress may make the plant more susceptible to other diseases or problems.
  • Sunscald ()
    Often the first symptom of sunscald is the reddish-brown discoloration of bark. Then, the bark shrinks, appearing sunken, splits and peels back in chunky patches exposing sapwood underneath. Often cankers develop. Severe sunscald may cause the entire trunk to be girdled, or only individual branches. Look for sunscald on the south, southwest or west side of trunks or branches. It most commonly affects trees suffering from water stress or young trees with thin bark. Newly planted or transplanted are most susceptible and container-grown plants are more likely to get sunscald than field-grown ones. Species particularly prone to sunscald include: Liriodendron, Acer, Tilia, Prunus, Pyrus, Malus, Juglans, and Ulmus.
  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.
  • Yellow-necked caterpillar (Datana ministra)
    Mature larvae are black except for a yellow orange neck and several yellow lines along the length of the body.

Tuliptree (Liriodendron )

  • Verticillium wilt (woody plants) (Verticillium species (W))
    The first signs of Verticillium wilt that you may notice are individual branches that suddenly wilt and die. Affected branches may occur on one side of the tree or may be scattered throughout the tree. If you carefully peel away the bark of these branches, you may see brown or green streaking in the sapwood. Streaking is common in trees such as maple or redbud, but often is not visible in ash.

Walnut (Juglans)

  • Yellow-necked caterpillar (Datana ministra)
    Mature larvae are black except for a yellow orange neck and several yellow lines along the length of the body.

Willow (Salix)

  • Lecanium scale (Parthenolecanium species)
    Family comprised of more than a dozen species of soft scales that are difficult to distinguish from one another but this group has no waxy covering, and lengths of 3-12 mm. Once females lay their eggs her hemispherical body dries and become brown.

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