Diagnostics

Woody Ornamentals-Deciduous-Tree

Ash (Fraxinus)

  • 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)

  • 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.
  • 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.
  • Common aphids (Several)
    Numerous species with colors ranging from yellow to red to black with short oval bodies. Aphids are small but vary in size.
  • Elm sawfly (Cimbex americana)
    Larvae are pale yellow to green in color with a dark stripe down the back, which develops a pebbly skin when full grown.
  • Gas Injury ()
    Symptoms of gas injury can range from slow growth to total plant death, and initially resemble symptoms of water stress. Gas injury may also be mistaken for compacted soil, root disease, herbicide injury or air pollution. Symptoms include: slow growth, small leaves, wilt and leaf drop. Roots may be bluish and water-soaked, and surrounding soils may turn bluish gray or black. The injury may progress over time. Gas injury may occur from gas released into the soil or into the air. Root zone injury from gas leaks in soil usually stems from gas or sewer-line breaks (rapid damage) or gases leaking from landfills (gradual damage). The extent of damage depends on the size of the leak, when it occurs (summer is worse), soil type (heavier is worse) and the amount of paving surrounding the plants. Gas injury due to atmospheric gas leaks usually stems from vents, chimneys, smokestacks or industrial equipment, and may or may not be phytotoxic. These releases are usually accidental and short-lived.
  • 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.
  • Manganese deficiency - woody plants ()
    Manganese (Mn) deficiency is most likely to occur in neutral to high pH soils that are also high in organic matter. This is common in the red soils of eastern Wisconsin, especially in low-lying, poorly drained areas, and on burned-over organic soils. Symptoms of Mn deficiency in broadleaf trees/shrubs manifest as interveinal chlorosis sometimes worsening to necrosis, undersized leaves, or leaves with curly, wavy or crinkled leaf margins. Symptoms appear on new growth first. Acer rubrum is particularly susceptible to this condition. In conifers, Mn deficiency symptoms closely resemble those of iron (Fe) deficiency: chlorotic and stunted new growth, with the older growth remaining green. Symptoms are more likely to appear on drought-stressed or acid-loving plants.
  • 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.
  • Scorch ()
    The primary symptom of scorch is the browning of leaf edges or needles. Sometimes there will be a distinct yellow band between the leaf edges and the green inner leaf. On conifers, especially spruce, affected needles will turn reddish-purple then brown. Scorch itself is a symptom and not the root cause of the problem. Woody species often affected by scorch include: Acer, Abies, Fraxinus, Pinus, Quercus and Tilia. Scorch may not affect the whole plant uniformly. It is not generally fatal. However, if extensive damage is present by mid-summer, the plant's ability to make food will be reduced and it may be more susceptible to winter damage. Scorch usually results from the following: insufficient water (due to drought, improper siting, impaired root systems); a response to an undesirable soil or air constituent (salt accumulation or atmospheric chemicals); or a response to fungal or bacteria pathogens.
  • 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-marked tussock moth (Orygia leucostigma)
    Larvae are up to 31 mm long with a reddish orange head and a cream colored body with distinct whitish yellow tufted hairs on the front and hind ends. Adults are moths.

Buckeye (Aesculus)

  • 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.
  • 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.
  • Gas Injury ()
    Symptoms of gas injury can range from slow growth to total plant death, and initially resemble symptoms of water stress. Gas injury may also be mistaken for compacted soil, root disease, herbicide injury or air pollution. Symptoms include: slow growth, small leaves, wilt and leaf drop. Roots may be bluish and water-soaked, and surrounding soils may turn bluish gray or black. The injury may progress over time. Gas injury may occur from gas released into the soil or into the air. Root zone injury from gas leaks in soil usually stems from gas or sewer-line breaks (rapid damage) or gases leaking from landfills (gradual damage). The extent of damage depends on the size of the leak, when it occurs (summer is worse), soil type (heavier is worse) and the amount of paving surrounding the plants. Gas injury due to atmospheric gas leaks usually stems from vents, chimneys, smokestacks or industrial equipment, and may or may not be phytotoxic. These releases are usually accidental and short-lived.
  • 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.
  • Manganese deficiency - woody plants ()
    Manganese (Mn) deficiency is most likely to occur in neutral to high pH soils that are also high in organic matter. This is common in the red soils of eastern Wisconsin, especially in low-lying, poorly drained areas, and on burned-over organic soils. Symptoms of Mn deficiency in broadleaf trees/shrubs manifest as interveinal chlorosis sometimes worsening to necrosis, undersized leaves, or leaves with curly, wavy or crinkled leaf margins. Symptoms appear on new growth first. Acer rubrum is particularly susceptible to this condition. In conifers, Mn deficiency symptoms closely resemble those of iron (Fe) deficiency: chlorotic and stunted new growth, with the older growth remaining green. Symptoms are more likely to appear on drought-stressed or acid-loving plants.
  • 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
  • Scorch ()
    The primary symptom of scorch is the browning of leaf edges or needles. Sometimes there will be a distinct yellow band between the leaf edges and the green inner leaf. On conifers, especially spruce, affected needles will turn reddish-purple then brown. Scorch itself is a symptom and not the root cause of the problem. Woody species often affected by scorch include: Acer, Abies, Fraxinus, Pinus, Quercus and Tilia. Scorch may not affect the whole plant uniformly. It is not generally fatal. However, if extensive damage is present by mid-summer, the plant's ability to make food will be reduced and it may be more susceptible to winter damage. Scorch usually results from the following: insufficient water (due to drought, improper siting, impaired root systems); a response to an undesirable soil or air constituent (salt accumulation or atmospheric chemicals); or a response to fungal or bacteria pathogens.
  • 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.
  • 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.
  • White-marked tussock moth (Orygia leucostigma)
    Larvae are up to 31 mm long with a reddish orange head and a cream colored body with distinct whitish yellow tufted hairs on the front and hind ends. Adults are moths.
  • Winter salt injury ()
    De-icing salts accumulate in the soil along streets/sidewalks or may be dispersed in an aerosol spray by fast-moving traffic and high winds along wet, salted roads. Salt spray can travel hundreds of feet from the roads where it originated. Symptoms can be similar to other abiotic plant problems, but there are tell-tale indicators including: Damage is more severe on sides of plants facing roads/sidewalks; severity of damage increases with volume/speed of traffic and amount of salt used; plants downwind from roads show more damage than those upwind; most damage occurs within 60' of road and decreases with distance; branches covered by snow or otherwise sheltered show no damage; branches growing above spray drift zone show no damage. Symptoms in deciduous plants include: delayed budbreak; reduced leaf size/stem growth; off-colored foliage; scorched leaves; no flowering; bud/twig death; and branch-tip dieback leading to 'witches' broom' growth below the dead area. Symptoms on conifers include: tips of mature needles turn brown or yellow, discoloration moves down needle eventually killing all of it, then needles fall off; twig dieback; and symptoms manifest only on sides of plants facing roads/sidewalks.

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.
  • 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.
  • Common aphids (Several)
    Numerous species with colors ranging from yellow to red to black with short oval bodies. Aphids are small but vary in size.
  • Gas Injury ()
    Symptoms of gas injury can range from slow growth to total plant death, and initially resemble symptoms of water stress. Gas injury may also be mistaken for compacted soil, root disease, herbicide injury or air pollution. Symptoms include: slow growth, small leaves, wilt and leaf drop. Roots may be bluish and water-soaked, and surrounding soils may turn bluish gray or black. The injury may progress over time. Gas injury may occur from gas released into the soil or into the air. Root zone injury from gas leaks in soil usually stems from gas or sewer-line breaks (rapid damage) or gases leaking from landfills (gradual damage). The extent of damage depends on the size of the leak, when it occurs (summer is worse), soil type (heavier is worse) and the amount of paving surrounding the plants. Gas injury due to atmospheric gas leaks usually stems from vents, chimneys, smokestacks or industrial equipment, and may or may not be phytotoxic. These releases are usually accidental and short-lived.
  • 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.
  • 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
  • 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.
  • 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.
  • White-marked tussock moth (Orygia leucostigma)
    Larvae are up to 31 mm long with a reddish orange head and a cream colored body with distinct whitish yellow tufted hairs on the front and hind ends. Adults are moths.

Elm (Ulmus)

  • Elm sawfly (Cimbex americana)
    Larvae are pale yellow to green in color with a dark stripe down the back, which develops a pebbly skin when full grown.
  • 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.

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.
  • 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.
  • Common aphids (Several)
    Numerous species with colors ranging from yellow to red to black with short oval bodies. Aphids are small but vary in size.
  • Gas Injury ()
    Symptoms of gas injury can range from slow growth to total plant death, and initially resemble symptoms of water stress. Gas injury may also be mistaken for compacted soil, root disease, herbicide injury or air pollution. Symptoms include: slow growth, small leaves, wilt and leaf drop. Roots may be bluish and water-soaked, and surrounding soils may turn bluish gray or black. The injury may progress over time. Gas injury may occur from gas released into the soil or into the air. Root zone injury from gas leaks in soil usually stems from gas or sewer-line breaks (rapid damage) or gases leaking from landfills (gradual damage). The extent of damage depends on the size of the leak, when it occurs (summer is worse), soil type (heavier is worse) and the amount of paving surrounding the plants. Gas injury due to atmospheric gas leaks usually stems from vents, chimneys, smokestacks or industrial equipment, and may or may not be phytotoxic. These releases are usually accidental and short-lived.
  • 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.
  • Winter salt injury ()
    De-icing salts accumulate in the soil along streets/sidewalks or may be dispersed in an aerosol spray by fast-moving traffic and high winds along wet, salted roads. Salt spray can travel hundreds of feet from the roads where it originated. Symptoms can be similar to other abiotic plant problems, but there are tell-tale indicators including: Damage is more severe on sides of plants facing roads/sidewalks; severity of damage increases with volume/speed of traffic and amount of salt used; plants downwind from roads show more damage than those upwind; most damage occurs within 60' of road and decreases with distance; branches covered by snow or otherwise sheltered show no damage; branches growing above spray drift zone show no damage. Symptoms in deciduous plants include: delayed budbreak; reduced leaf size/stem growth; off-colored foliage; scorched leaves; no flowering; bud/twig death; and branch-tip dieback leading to 'witches' broom' growth below the dead area. Symptoms on conifers include: tips of mature needles turn brown or yellow, discoloration moves down needle eventually killing all of it, then needles fall off; twig dieback; and symptoms manifest only on sides of plants facing roads/sidewalks.

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.
  • Black walnut toxicity (herbaceous) ()
    Plants sensitive to juglone, a toxic substance produced by black walnut trees and to a lesser extent, butternut trees and shagbark hickories, may be stunted, have yellow or brown twisted leaves, may exhibit wilting or some or all of the plant parts, and die over time. Often an affected plant's vascular tissue will be discolored. Symptoms may occur rapidly, even within a few days of being transplanted into a walnut tree's root zone. Some plants may survive for years near a young walnut tree, only to succumb as the tree increases in size.
  • 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.
  • Common aphids (Several)
    Numerous species with colors ranging from yellow to red to black with short oval bodies. Aphids are small but vary in size.
  • Gas Injury ()
    Symptoms of gas injury can range from slow growth to total plant death, and initially resemble symptoms of water stress. Gas injury may also be mistaken for compacted soil, root disease, herbicide injury or air pollution. Symptoms include: slow growth, small leaves, wilt and leaf drop. Roots may be bluish and water-soaked, and surrounding soils may turn bluish gray or black. The injury may progress over time. Gas injury may occur from gas released into the soil or into the air. Root zone injury from gas leaks in soil usually stems from gas or sewer-line breaks (rapid damage) or gases leaking from landfills (gradual damage). The extent of damage depends on the size of the leak, when it occurs (summer is worse), soil type (heavier is worse) and the amount of paving surrounding the plants. Gas injury due to atmospheric gas leaks usually stems from vents, chimneys, smokestacks or industrial equipment, and may or may not be phytotoxic. These releases are usually accidental and short-lived.
  • 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.
  • Manganese deficiency - woody plants ()
    Manganese (Mn) deficiency is most likely to occur in neutral to high pH soils that are also high in organic matter. This is common in the red soils of eastern Wisconsin, especially in low-lying, poorly drained areas, and on burned-over organic soils. Symptoms of Mn deficiency in broadleaf trees/shrubs manifest as interveinal chlorosis sometimes worsening to necrosis, undersized leaves, or leaves with curly, wavy or crinkled leaf margins. Symptoms appear on new growth first. Acer rubrum is particularly susceptible to this condition. In conifers, Mn deficiency symptoms closely resemble those of iron (Fe) deficiency: chlorotic and stunted new growth, with the older growth remaining green. Symptoms are more likely to appear on drought-stressed or acid-loving plants.
  • 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.
  • 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.

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.
  • 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.
  • Common aphids (Several)
    Numerous species with colors ranging from yellow to red to black with short oval bodies. Aphids are small but vary in size.
  • 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.
  • Gas Injury ()
    Symptoms of gas injury can range from slow growth to total plant death, and initially resemble symptoms of water stress. Gas injury may also be mistaken for compacted soil, root disease, herbicide injury or air pollution. Symptoms include: slow growth, small leaves, wilt and leaf drop. Roots may be bluish and water-soaked, and surrounding soils may turn bluish gray or black. The injury may progress over time. Gas injury may occur from gas released into the soil or into the air. Root zone injury from gas leaks in soil usually stems from gas or sewer-line breaks (rapid damage) or gases leaking from landfills (gradual damage). The extent of damage depends on the size of the leak, when it occurs (summer is worse), soil type (heavier is worse) and the amount of paving surrounding the plants. Gas injury due to atmospheric gas leaks usually stems from vents, chimneys, smokestacks or industrial equipment, and may or may not be phytotoxic. These releases are usually accidental and short-lived.
  • 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.
  • 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.
  • Spider mites (Tetranychidae family)
    Family includes the majority of mites that cause plant damage. Larvae are smaller with 6 legs with adults being larger and having 8 legs. Spider mites vary in color and size by species with many being microscopic.

Hickory (Carya)

  • 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.
  • 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.
  • Common aphids (Several)
    Numerous species with colors ranging from yellow to red to black with short oval bodies. Aphids are small but vary in size.
  • Gas Injury ()
    Symptoms of gas injury can range from slow growth to total plant death, and initially resemble symptoms of water stress. Gas injury may also be mistaken for compacted soil, root disease, herbicide injury or air pollution. Symptoms include: slow growth, small leaves, wilt and leaf drop. Roots may be bluish and water-soaked, and surrounding soils may turn bluish gray or black. The injury may progress over time. Gas injury may occur from gas released into the soil or into the air. Root zone injury from gas leaks in soil usually stems from gas or sewer-line breaks (rapid damage) or gases leaking from landfills (gradual damage). The extent of damage depends on the size of the leak, when it occurs (summer is worse), soil type (heavier is worse) and the amount of paving surrounding the plants. Gas injury due to atmospheric gas leaks usually stems from vents, chimneys, smokestacks or industrial equipment, and may or may not be phytotoxic. These releases are usually accidental and short-lived.
  • 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.
  • Manganese deficiency - woody plants ()
    Manganese (Mn) deficiency is most likely to occur in neutral to high pH soils that are also high in organic matter. This is common in the red soils of eastern Wisconsin, especially in low-lying, poorly drained areas, and on burned-over organic soils. Symptoms of Mn deficiency in broadleaf trees/shrubs manifest as interveinal chlorosis sometimes worsening to necrosis, undersized leaves, or leaves with curly, wavy or crinkled leaf margins. Symptoms appear on new growth first. Acer rubrum is particularly susceptible to this condition. In conifers, Mn deficiency symptoms closely resemble those of iron (Fe) deficiency: chlorotic and stunted new growth, with the older growth remaining green. Symptoms are more likely to appear on drought-stressed or acid-loving plants.
  • 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.
  • 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.
  • Scorch ()
    The primary symptom of scorch is the browning of leaf edges or needles. Sometimes there will be a distinct yellow band between the leaf edges and the green inner leaf. On conifers, especially spruce, affected needles will turn reddish-purple then brown. Scorch itself is a symptom and not the root cause of the problem. Woody species often affected by scorch include: Acer, Abies, Fraxinus, Pinus, Quercus and Tilia. Scorch may not affect the whole plant uniformly. It is not generally fatal. However, if extensive damage is present by mid-summer, the plant's ability to make food will be reduced and it may be more susceptible to winter damage. Scorch usually results from the following: insufficient water (due to drought, improper siting, impaired root systems); a response to an undesirable soil or air constituent (salt accumulation or atmospheric chemicals); or a response to fungal or bacteria pathogens.
  • 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.
  • Spider mites (Tetranychidae family)
    Family includes the majority of mites that cause plant damage. Larvae are smaller with 6 legs with adults being larger and having 8 legs. Spider mites vary in color and size by species with many being microscopic.

Linden (Tilia)

  • White-marked tussock moth (Orygia leucostigma)
    Larvae are up to 31 mm long with a reddish orange head and a cream colored body with distinct whitish yellow tufted hairs on the front and hind ends. Adults are moths.

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)

  • 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.
  • 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.
  • Common aphids (Several)
    Numerous species with colors ranging from yellow to red to black with short oval bodies. Aphids are small but vary in size.
  • Elm sawfly (Cimbex americana)
    Larvae are pale yellow to green in color with a dark stripe down the back, which develops a pebbly skin when full grown.
  • Gas Injury ()
    Symptoms of gas injury can range from slow growth to total plant death, and initially resemble symptoms of water stress. Gas injury may also be mistaken for compacted soil, root disease, herbicide injury or air pollution. Symptoms include: slow growth, small leaves, wilt and leaf drop. Roots may be bluish and water-soaked, and surrounding soils may turn bluish gray or black. The injury may progress over time. Gas injury may occur from gas released into the soil or into the air. Root zone injury from gas leaks in soil usually stems from gas or sewer-line breaks (rapid damage) or gases leaking from landfills (gradual damage). The extent of damage depends on the size of the leak, when it occurs (summer is worse), soil type (heavier is worse) and the amount of paving surrounding the plants. Gas injury due to atmospheric gas leaks usually stems from vents, chimneys, smokestacks or industrial equipment, and may or may not be phytotoxic. These releases are usually accidental and short-lived.
  • 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.
  • Manganese deficiency - woody plants ()
    Manganese (Mn) deficiency is most likely to occur in neutral to high pH soils that are also high in organic matter. This is common in the red soils of eastern Wisconsin, especially in low-lying, poorly drained areas, and on burned-over organic soils. Symptoms of Mn deficiency in broadleaf trees/shrubs manifest as interveinal chlorosis sometimes worsening to necrosis, undersized leaves, or leaves with curly, wavy or crinkled leaf margins. Symptoms appear on new growth first. Acer rubrum is particularly susceptible to this condition. In conifers, Mn deficiency symptoms closely resemble those of iron (Fe) deficiency: chlorotic and stunted new growth, with the older growth remaining green. Symptoms are more likely to appear on drought-stressed or acid-loving plants.
  • 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
  • Scorch ()
    The primary symptom of scorch is the browning of leaf edges or needles. Sometimes there will be a distinct yellow band between the leaf edges and the green inner leaf. On conifers, especially spruce, affected needles will turn reddish-purple then brown. Scorch itself is a symptom and not the root cause of the problem. Woody species often affected by scorch include: Acer, Abies, Fraxinus, Pinus, Quercus and Tilia. Scorch may not affect the whole plant uniformly. It is not generally fatal. However, if extensive damage is present by mid-summer, the plant's ability to make food will be reduced and it may be more susceptible to winter damage. Scorch usually results from the following: insufficient water (due to drought, improper siting, impaired root systems); a response to an undesirable soil or air constituent (salt accumulation or atmospheric chemicals); or a response to fungal or bacteria pathogens.
  • 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.
  • 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.
  • White-marked tussock moth (Orygia leucostigma)
    Larvae are up to 31 mm long with a reddish orange head and a cream colored body with distinct whitish yellow tufted hairs on the front and hind ends. Adults are moths.
  • Winter salt injury ()
    De-icing salts accumulate in the soil along streets/sidewalks or may be dispersed in an aerosol spray by fast-moving traffic and high winds along wet, salted roads. Salt spray can travel hundreds of feet from the roads where it originated. Symptoms can be similar to other abiotic plant problems, but there are tell-tale indicators including: Damage is more severe on sides of plants facing roads/sidewalks; severity of damage increases with volume/speed of traffic and amount of salt used; plants downwind from roads show more damage than those upwind; most damage occurs within 60' of road and decreases with distance; branches covered by snow or otherwise sheltered show no damage; branches growing above spray drift zone show no damage. Symptoms in deciduous plants include: delayed budbreak; reduced leaf size/stem growth; off-colored foliage; scorched leaves; no flowering; bud/twig death; and branch-tip dieback leading to 'witches' broom' growth below the dead area. Symptoms on conifers include: tips of mature needles turn brown or yellow, discoloration moves down needle eventually killing all of it, then needles fall off; twig dieback; and symptoms manifest only on sides of plants facing roads/sidewalks.

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)

  • Oak leaf skeletonizer (Bucculatrix ainsliella)
    Larvae are pale yellow, sometimes tinted with green and approximately 7mm long. If larvae are disturbed they may spin long silken threads and hang from branches. White webs or cocoons may also be present.
  • Oak leafminer (Cameraria species)
    Several species cause mines in oak leaves.
  • 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.

Plum / Cherry (Prunus)

  • 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.

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.
  • 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.
  • Gas Injury ()
    Symptoms of gas injury can range from slow growth to total plant death, and initially resemble symptoms of water stress. Gas injury may also be mistaken for compacted soil, root disease, herbicide injury or air pollution. Symptoms include: slow growth, small leaves, wilt and leaf drop. Roots may be bluish and water-soaked, and surrounding soils may turn bluish gray or black. The injury may progress over time. Gas injury may occur from gas released into the soil or into the air. Root zone injury from gas leaks in soil usually stems from gas or sewer-line breaks (rapid damage) or gases leaking from landfills (gradual damage). The extent of damage depends on the size of the leak, when it occurs (summer is worse), soil type (heavier is worse) and the amount of paving surrounding the plants. Gas injury due to atmospheric gas leaks usually stems from vents, chimneys, smokestacks or industrial equipment, and may or may not be phytotoxic. These releases are usually accidental and short-lived.
  • 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.
  • 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.
  • Scorch ()
    The primary symptom of scorch is the browning of leaf edges or needles. Sometimes there will be a distinct yellow band between the leaf edges and the green inner leaf. On conifers, especially spruce, affected needles will turn reddish-purple then brown. Scorch itself is a symptom and not the root cause of the problem. Woody species often affected by scorch include: Acer, Abies, Fraxinus, Pinus, Quercus and Tilia. Scorch may not affect the whole plant uniformly. It is not generally fatal. However, if extensive damage is present by mid-summer, the plant's ability to make food will be reduced and it may be more susceptible to winter damage. Scorch usually results from the following: insufficient water (due to drought, improper siting, impaired root systems); a response to an undesirable soil or air constituent (salt accumulation or atmospheric chemicals); or a response to fungal or bacteria pathogens.
  • 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.
  • 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.
  • White-marked tussock moth (Orygia leucostigma)
    Larvae are up to 31 mm long with a reddish orange head and a cream colored body with distinct whitish yellow tufted hairs on the front and hind ends. Adults are moths.

Russian Olive (Elaeagnus )

  • 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)

  • 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.
  • 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.
  • Gas Injury ()
    Symptoms of gas injury can range from slow growth to total plant death, and initially resemble symptoms of water stress. Gas injury may also be mistaken for compacted soil, root disease, herbicide injury or air pollution. Symptoms include: slow growth, small leaves, wilt and leaf drop. Roots may be bluish and water-soaked, and surrounding soils may turn bluish gray or black. The injury may progress over time. Gas injury may occur from gas released into the soil or into the air. Root zone injury from gas leaks in soil usually stems from gas or sewer-line breaks (rapid damage) or gases leaking from landfills (gradual damage). The extent of damage depends on the size of the leak, when it occurs (summer is worse), soil type (heavier is worse) and the amount of paving surrounding the plants. Gas injury due to atmospheric gas leaks usually stems from vents, chimneys, smokestacks or industrial equipment, and may or may not be phytotoxic. These releases are usually accidental and short-lived.
  • 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.
  • Manganese deficiency - woody plants ()
    Manganese (Mn) deficiency is most likely to occur in neutral to high pH soils that are also high in organic matter. This is common in the red soils of eastern Wisconsin, especially in low-lying, poorly drained areas, and on burned-over organic soils. Symptoms of Mn deficiency in broadleaf trees/shrubs manifest as interveinal chlorosis sometimes worsening to necrosis, undersized leaves, or leaves with curly, wavy or crinkled leaf margins. Symptoms appear on new growth first. Acer rubrum is particularly susceptible to this condition. In conifers, Mn deficiency symptoms closely resemble those of iron (Fe) deficiency: chlorotic and stunted new growth, with the older growth remaining green. Symptoms are more likely to appear on drought-stressed or acid-loving plants.
  • 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
  • Scorch ()
    The primary symptom of scorch is the browning of leaf edges or needles. Sometimes there will be a distinct yellow band between the leaf edges and the green inner leaf. On conifers, especially spruce, affected needles will turn reddish-purple then brown. Scorch itself is a symptom and not the root cause of the problem. Woody species often affected by scorch include: Acer, Abies, Fraxinus, Pinus, Quercus and Tilia. Scorch may not affect the whole plant uniformly. It is not generally fatal. However, if extensive damage is present by mid-summer, the plant's ability to make food will be reduced and it may be more susceptible to winter damage. Scorch usually results from the following: insufficient water (due to drought, improper siting, impaired root systems); a response to an undesirable soil or air constituent (salt accumulation or atmospheric chemicals); or a response to fungal or bacteria pathogens.
  • 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.
  • Spider mites (Tetranychidae family)
    Family includes the majority of mites that cause plant damage. Larvae are smaller with 6 legs with adults being larger and having 8 legs. Spider mites vary in color and size by species with many being microscopic.
  • 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.
  • Winter salt injury ()
    De-icing salts accumulate in the soil along streets/sidewalks or may be dispersed in an aerosol spray by fast-moving traffic and high winds along wet, salted roads. Salt spray can travel hundreds of feet from the roads where it originated. Symptoms can be similar to other abiotic plant problems, but there are tell-tale indicators including: Damage is more severe on sides of plants facing roads/sidewalks; severity of damage increases with volume/speed of traffic and amount of salt used; plants downwind from roads show more damage than those upwind; most damage occurs within 60' of road and decreases with distance; branches covered by snow or otherwise sheltered show no damage; branches growing above spray drift zone show no damage. Symptoms in deciduous plants include: delayed budbreak; reduced leaf size/stem growth; off-colored foliage; scorched leaves; no flowering; bud/twig death; and branch-tip dieback leading to 'witches' broom' growth below the dead area. Symptoms on conifers include: tips of mature needles turn brown or yellow, discoloration moves down needle eventually killing all of it, then needles fall off; twig dieback; and symptoms manifest only on sides of plants facing roads/sidewalks.

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)

  • White-marked tussock moth (Orygia leucostigma)
    Larvae are up to 31 mm long with a reddish orange head and a cream colored body with distinct whitish yellow tufted hairs on the front and hind ends. Adults are moths.

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