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Discoloration of Vascular Tissue
  Most deciduous trees and many shrubs are susceptible to a disease called Verticillium wilt. Conifers do not appear to be susceptible.   Symptoms Early indications that a tree has Verticillium wilt include heavy seed production, leaves that are smaller than normal, and the browning of the margins of leaves. […]

Verticillium Wilt of Woody Ornamental’s


Sycamore Tree Fungus Powdery Mildew
Sycamore Tree Diseases  Anthracnose   Symptoms Dead twigs and branches have sunken cankers. Bud death followed by new bud formation and more bud death results in witches’ broom-like proliferation of branch ends as well as very crooked branching patterns. Black fungal fruiting structures are visible on the bark covering newly […]

Sycamore Tree Diseases – Symptoms & Control



Spruce Tree Rhizophaeria Needlecast
Spruce Tree Diseases Cytospora Canker   Symptoms Sunken dead ares of bark and underlying wood form on the lower branches of the trees girdling small branches in 1 or 2 years and large branches after several years. Resin flows out of the cankers and may drip down on lower branches. […]

Spruce Tree Diseases – Symptoms & Control


Fruiting Bodies on Cone Scales
Sphaeropsis (Diplodia) Tip Blight of Pine Trees Austrian, Scots, Ponderosa, Mugho, Red and other 2 and 3 needled Pines are susceptible to the killing of shoot tips and branches cause by the fungus Sphaeropsis sapinea Symptoms include the browning of needles on new shoots as the needles grow from the […]

Sphaeropsis (Diplodia) Tip Blight of Pine Trees


Pine Tree Diseases Cyclaneusma Needlecast   Symptoms Needles on Pines yellow and have dark-brown bands from September through December, the year after infection, or from April through June, 2 years after infection. The brown bars become filled with a tan fungal fruiting structure, which opens wide under very moist conditions. […]

Pine Tree Diseases – Symptoms & Management



Scheduling Disease Control in Woody Ornamental’s The scheduling of effective disease management measures is not a simple task nor can it be consistent. The activities of the organisms that cause plant disease are not governed by the clock. Their activity is influenced by temperature, relative humidity, soil moisture and other […]

Scheduling Disease Control in Woody Ornamental’s


Rose Shrub Diseases - Virus
Rose Diseases Anthracnose   Symptoms Dark purple to black spots are bordered by a narrow, dull-brown band. Centers of spots turn gray and fall out. Spots similar to leaf spots form on canes.   Management ZeroTol Fungicide is a ready to use spray that provides immediate control for anthracnose on […]

Rose Diseases: Kockouts & Double Knockout Roses


The bacterium Pseudomonas syringae, is an opportunistic pathogen that can attack a wide variety of woody plants especially when they are damaged by frost or injured in some way. While there are a number of strains of this organism, syringae is most important on woody plants.  Symptoms Common, Persain, Chinese, and Japanese […]

Pseudomonas Syringae: A Common Pathogen on Woody Plants



Poplar Tree Disease Shoot Blight
Poplar Tree Diseases   Cryptodiaporthe Canker   Symptoms At first, a few twigs are killed. The fungus spreads rapidly to cause many variously shaped cankers and kill large branches as it does so. Perennial Canker formation leads to leaf yellowing, premature defoliation, and water sprout formation. Green-Brown material filled with […]

Poplar Tree Diseases


Black Spot Shurb Disease on Rose BUsh
Rose Black Spot Disease   A common disease of Roses, called Black Spot Disease , is caused by the fungus Diplocarpon rosae. This fungus attacks young expanding leaves. Fungal spored which were formed on infected fallen leaves or on canse are splashed to the new lower leaves of roses in […]

Black Spot Disease on Roses


Species of fungus-like organisms belonging to the genus Phytophthora are soil-borne or plant-borne and all are plant pathogens. Some species of Phytophthora attack woody ornamentals including Arborvitae, Azalea, Dogwood, Forsythia, Fir, Hemlock, Holly, Juniper, Maple, Rhododendron, and White Pine. Other species attack herbaceous plants including Annual Vinca (Catharanthus), Begonia, Poinsettias, […]

Phytophthora Root Rot on Woody Ornamentals



 Perennial Diseases   Yarrow:  Diseases of Yarrow-Botrytis on yarrow flowers are often seriously inflicted with the disease Botrytis. Botrytis known as gray mold appears as brown dead areas and under proper moisture   may have a gray fuzzy appearance. It attacks buds, flowers, leaves, and stems. It may eventually kill […]

More Perennials and Perennial Diseases!


 Viola Perennial Shrub Diseases:   Aster Yellows: Symptoms – Leaves are yellowed and narrow rather than oval. An abnormally high number of shoots form. Management – Remove infected plants. Control leafhoppers.   Bacterial Infection: Symptoms – An abnormally high number of shoots form Management – Remove infected plants. Black Root Rot: Symptoms – Plants are yellowed, stunted and die. Management – Try […]

Viola Perennial Shrub Diseases – Symptoms & Control


 Rudbeckia (black eyed susan) Perennial Shrub Diseases:   Aster Yellows: Symptoms – Leaf-like structures form where flower parts should be located. Plants may branch abnormally heavily (witches’ broom), leaves may be yellow and plants may be stunted. Management – Remove and destroy infected plants. Control leafhoppers early in the season with insecticides in order […]

Rudbeckia (Black Eyed Susan) Perennial Shrub Diseases – Symptoms & ...



Daylily Perennial Shrub Diseases:   Colletotrichum Leaf Spot or Leaf Scorch: Symptoms – Leaf tissue dies in a streak along the mid-vein. Management – Remove infected leaves. Destroy leaf debris at the end of the season. Avoid overhead irrigation.   Leaf Streak or Red Leaf Streak: Symptoms –  Reddish fleck form on the leaves as […]

Daylily Perennial Shrub Diseases – Symptoms & Control


 Blanket Flower Perennial Shrub Diseases:   Aster Yellows: Symptoms – Leaves are yellowed and flowers do not appear normal or of good quality. Management –  Remove and destroy infected plants. Control leafhoppers early in the season with insecticides in order to suppress spread of the pathogen   Bacterial Leaf Spot: Symptoms –  Areas between veins […]

Blanket Flower Perennial Shrub Diseases – Symptoms & Control


 Coreopsis Perennial Shrub Diseases: Aster Yellows: Symptoms – This virus is moved from infected clematis and some weeds by nematodes. Remove infected plants Management – Maintain good leafhopper control and eliminate nearby weeds that harbor aster yellows.   Bacterial Leaf Spot: Symptoms – Irregular brown blotches and spots develop on leaves Management – Water in a manner that […]

Coreopsis Perennial Shrub Diseases – Symptoms & Control



 Coneflower Perennial Shrub Diseases: Alternaria Leaf Spot: Symptoms – Small dark brown to black leaf spots become oblong and develop lighter-colored centers as they enlarge. Spots on young plants are often along the midrib. Management – Water in a manner that keeps moisture off the leaves and stems. Apply PureSpray Green to help protect […]

Coneflower Perennial Shrub Diseases – Symptoms & Control


Clematis Perennial Shrub Diseases Leaf Spot: Symptoms – Large spots form on the leaves, become tan or black in color and may have a zonate pattern within them. Management – Ensure good air circulation around clematis stems. Remove infected leaves as they are detected. Irrigate plants in a manner that keeps water off the […]

Clematis Perennial Shrub Diseases – Symptoms & Control


Perennial Shrub Diseases   Time and Time again it seems that we, as homeowners, are always fighting a never ending battle when it comes to disease and fungus on our Perennial Shrubs.  Shrub diseases can have a major impact on the entire landscape and if not properly treated can lead […]

Perennial Shrub Diseases



Astilbe Perennial Shrub Diseases:   Flower Failure: Symptoms – Plants do not flower but otherwise appear healthy. Management – Divide and replant to alleviate overcrowding. Foliar Nematode: Symptoms – Brown areas on the leaf are restricted in shape by leaf veins. These angular spots are usually seen on the lower leaves. Management – Remove the leaves […]

Astilbe Perennial Shrub Diseases – Symptoms & Control





Oak Tree Diseases - Blisters
Oak Tree Diseases Anthracnose   Symptoms During wet weather, young leaves are blighted as bud break occurs or large dead areas form between the leaf veins primarily on lower branches. Winter twig dieback may occur. Slightly raised, brown dots (fungal fruiting structures) form on the lower surface of leaves and […]

Oak Tree Diseases


Nematode Diseases
Nematode Diseases   Nematodes are soil-dwelling non-segmented roundworms, usually less than 0.02 in. long. Those that feed on plants have a hollow spear-like mouth part (stylet) that is pushed into the plant cell. The worm forces enzymes through the hollow stylet into the cell where cell components are digested and […]

Nematode caused Diseases on Woody Ornamentals


Evergreen Needlecast Diseases are caused by several fungi. Needles infected with fungi generally fall several months after the actual period of infection. The period of greatestinfection for most needlecast fungi is during the late Spring and early Summer months. Symptoms, the visible indication that the needle is diseased, do not […]

Evergreen Needlecast Diseases



Maple Tree Diseases   Anthracnose   Symptoms Norway maple: narrrow, purple to brown streaks occur along the leaf veins. Sugar maple: large, irregular, brown or red-brown areas develop along and between the veins similar to injury due to drought and heat stress. Small, brown fruiting structures of the fungus are […]

Maple Tree Diseases


Lilac Shrub Diseases   Ascochyta Blight   Symptoms In the Spring, the current year’s shoots and flower stalks are girdled, wilted, and brown. The base of the dead area is tan to gray and shriveled. In wet weather, dark gray pimple-like fungal fruiting structures dot the dead tissue. In Summer […]

Lilac Shrub Diseases


  Juniper Twig Blight Disease   Junipers are suceptible to a disease that results in the death of twig tips. The disease is most severe in nursery stock and seedlings where plants are grown closely together. However, established plants are also attached. Two different fungi have been found causing this […]

Juniper Twig Blight Disease



Hydrangea Shrub Diseases   Botrytis Blight   Symptoms Petals turn brown and fall. Leaf spots form, especially where faded petals have fallen. Flower buds are killed before opening.   Management Space plants to insure good air circulation. Maintain low humidity. Avoid watering late in the day. Remove crop debris. Apply […]

Hydrangea Shrub Diseases


 Holly Diseases   Leaf Scorch   Symptoms Circular to irregular, tan spots appear in early Spring or Summer. Tiny, black fungal fruiting structures pepper the spot surface as a result of attack by the secondary fungus.   Management No control is recommended   Nematodes   Symptoms Yellowing, stunting, and twig […]

Holly Diseases


Forsythia Diseases Gall   Symptoms Knobby galls from along forsythia branches.   Management Prune infected branches. Disinfect the pruning shears thoroughly after use.     Twig Blight   Symptoms The ends of lower branches, especially those near the ground, die. Black nodules of fungal tissue are found inside the stems […]

Forsythia Diseases



Fire Blight is a bacterium that can attack more than 75 species of trees and shrubs including apple, pear, quince, mountain ash, crabapple, hawthorn, cotoneaster, and serviceberry. The bacterium over winters on infected plants in darkened, slightly sunken cankers. In the spring the bacteria are dispersed by insects, rain, wind, […]

Fire Blight



 Elm Tree Diseases   Black Leaf Spot   Symptoms Small, black, slightly raised, rough spots form on leaves. Leaves yellow and fall prematurely   Management Apply PureSpray Green. An Organic Spray that is very effective in controlling Leaf Spot. BUY NOW   Botryodiplodia Canker   Symptoms Cankers form on twigs […]

Elm Tree Diseases



Dogwood Tree Diseases    Anthracnose & Decline Symptoms Brown spots up to 1/4 inch in diameter go entirely through the leaf and have reddish-brown halos. Tiny, dark-brown fungal fruiting structures dot the brown areas. Small, reddish-brown spots without brown centers may pepper portions of the leaf or extend along veins. […]

Dogwood Tree Diseases


Root Death is an important cause of poor plant health in woody plants. When roots are killed, the plant is not able to take up sufficient water or nutrients to support the development of branches, leaves, flowers, or fruit. Usually, the above-ground symptoms appear long after root death has been […]

Diagnosing Root Death in Woody Ornamentals


Blue and Norway Spruces are susceptible to a branch killing disease called Cytospora Canker. Cankers are dead, sunken areas of bark and underlying wood that form on the lower branches, eventually making its way towards the top of the tree. Resin flows out of the cankers and may drip down […]

Cytospora on Spruce




Crabapple Diseases Botryosphaeria Canker   Symptoms Leaves on infected branches wilt and die. Branches die back and become covered with dark-brown to black, pimple-like fungal fruiting structures. Wood under the bark is dark brown.   Management Trees most susceptible are those under drought stress. Be sure to water the plant […]

Crabapple Diseases


  Cherry Tree Diseases   Black Knot   Symptoms Dark-brown to black, hard swellings form on twigs and branches. At first these galls are small but continue to enlarge each year, becoming very rough. Each Spring, galls are covered with dark, olive-green, felt-like growth. Branches may be girdled and die. […]

Cherry Tree Diseases



Cedar Apple Rust and closely related diseases, cedar-quince, cedar-hawthorn, and Japanese apple rusts are caused by fungi belonging to the genus Gymnosporangium. These fungi require two different living host plants in order to complete their life cycles. If either host plant is not present, the fungus dies. Juniper, sometimes called […]

Cedar Apple Rust & Related Rusts on Ornamental Trees


Localized areas of dead bark and underlying wood on twigs, branches and trunks are called cankers. Cankers can be cause either by living organisms, including fungi and bacteria, or by non-living things such as excessive low or high temperature or hail. Many fungi that cause Cankers normally inhabit the surface […]

Cankers of Hardwood Deciduous Trees


Boxwood Diseases Decline   Symptoms Stunted growth and dieback occur. Young foliage turns grayish green or bronze and finally straw colored. Old leaves fall prematurely. Middle or top branches die. Sunken cankers form at the soil line or on branches in the crotches where dead leaves accumulate. Wood under the […]

Boxwood Diseases



Cherry Tree Disease – Black Knot Black Knot causes the formation of dark brown to black, long, swollen galls or knots on the branches of most types of cultivated plums, prunes and cherries. The disease is very destructive, killing twigs and limbs, and occasionally whole trees. Although there are no […]

Black Knot – Cherry Tree Disease


          Botryosphaeria Canker   Symptoms Rough, sunken, dark-brown areas form around wounds or natural openings in the bark. The wood of a recently killed branch is lighter brown than the pith. Dead bark falls off the cankered area. Leaves on affected branches wilt as affected branches […]

Azalea & Rhododendron Shrub Diseases


Anthracnose   Symptoms Leaves develop irregular water soaked or blackish green blotches that eventually turn black or brown. The blotches develop from the margin inward and are usually limited only by the midvein. Leaflets curl toward the blighted area. Ash anthracnose symptoms develop in mid spring and are often followed […]

Ash Tree Diseases



      Branchlet   Symptoms The oldest branchlets turn brown in autumn and fall off   Management Branchlets rather than scale leaves are shed in autumn as a normal part of the plant development   Kabatina Twig Blight   Symptoms Tips of one-year-old branches die and turn brown or […]

Arborvitae Diseases, Symptoms & Management – Bagworms, Spidermites & More!


Ash, Oak, Sycamore, Maple, Dogwood, and many other deciduous hardwoods are susceptible to a leaf disease called anthracnose   Symptoms Include: Small dead spots on leaves Dead leaf margins and tips Brown, dead areas along leaf veins Large dead blotches between leaf veins Premature defoliation Twig death Bud killing early […]

Anthracnose on Shade Trees