Share

All Fact Sheets

Informational table showing disease name, symptoms, pathogen/cause, and management of Arborvitae diseases.

Armillaria root rot, sometimes called shoestring root rot, is caused by various species of the fungus Armillaria. Susceptible plants include most deciduous and coniferous species.

Informational table showing disease name, symptoms, pathogen/cause, and management of Ash diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Azalea and Rhododendron diseases.

Leaf scorch, sometimes called marginal leaf burn, describes the death of tissue along the edge of the leaf. This symptom develops when sufficient water does not reach the leaf margin cells.

Many mature trees, including elms, oak, tulip poplar, and maple, exhibit large light or dark vertical streaks on their trunks resulting from slimy liquid oozing out of crack or wounds and running down the bark. This is called 'slime flux'.

Informational table showing disease name, symptoms, pathogen/cause, and management of Beech diseases.

The fungus Plowrightia morbosa (Apiosporina) 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.

Informational table showing disease name, symptoms, pathogen/cause, and management of Boston Ivy (Parthenocissus) diseases.

The fungus Botryosphaeria can cause a branch dieback on horsechestnut, redbud, dogwood, beech, walnut, tulip poplar, sweetgum, crabapple, pine, oak, rhododendron, azalea, rose, willow, elm, yew, and many other woody ornamentals.

Informational table showing disease name, symptoms, pathogen/cause, and management of Boxwood diseases.

Localized areas of dead bark and underlying wood on twigs, branches and trunks are called cankers.

London plane and sycamore trees are susceptible to a fungus, Ceratocystis fimbriata f. sp. platani, that is lethal. The living cells of the wood in the phloem, cambium and sapwood are invaded quickly soon after a fresh wound exposes those cells.

Informational table showing disease name, symptoms, pathogen/cause, and management of Catalpa 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.

Informational table showing disease name, symptoms, pathogen/cause, and management of Cherry diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Chestnut diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Cotoneaster diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Crabapple diseases.

Crown gall is caused by bacteria belonging to the genus and species Agrobacterium tumefaciens. This bacterium can infect a wide range of herbaceous and woody plants.

Blue and Norway spruces are susceptible to a branch killing disease caused by the fungus Cytospora kunzei.

Informational table showing disease name, symptoms, pathogen/cause, and management of Dogwood 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.

Informational table showing disease name, symptoms, pathogen/cause, and management of Douglas-Fir diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Elm diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of English Ivy (Hedera) diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Euonymus diseases.

The fungus Eutypella parasitica kills the growing layer of cells under the bark, the cambium, and causes a pronounced bulge of callus to develop around the infected area of red, sugar, silver, Norway, and other maples.

Fire blight is a disease caused by the bacterium Erwinia amylovora. This bacterium can attack more than 75 species of trees and shrubs including apple, pear, quince, mountain ash, crabapple, hawthorn, cotoneaster, serviceberry, and pyracantha.

Informational table showing disease name, symptoms, pathogen/cause, and management of Forsythia diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Hackberry diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Hawthorn diseases.

Most plant diseases cause a loss of yield or damage the aesthetic qualities of the infected plant. Certain diseases of trees, however, weaken their structure and create a hazardous situation where property damage or serious bodily injury could result from falling limbs or the toppling of the entire tree.

Informational table showing disease name, symptoms, pathogen/cause, and management of Hemlock diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Hickory diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Holly diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Honeysuckle diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Horsechestnut diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Hydrangea diseases.

Some devastating pathogens in woody ornamentals are moved from plant to plant or 'vectored' by insects.

A tree presents a hazard if a defective part poses a high risk, upon its structural failure, to cause personal injury or property damage.

Informational table showing disease name, symptoms, pathogen/cause, and management of Juniper diseases.

Junipers (Juniperus sp.), also known as red cedars are susceptible to a disease that results in the death of twig tips.

Informational table showing disease name, symptoms, pathogen/cause, and management of Leucothoe diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Lilac diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Maple diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Mountain Ash diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Mountain Laurel diseases.

The fungus Nectria invades wood damaged by freezing, hail, animals and insects.

Needlecast diseases of evergreens are caused by several fungi. We have much to learn about when these fungi attack a tree, how long the fungus must be in the tree before needles are shed, when is the best time to apply a fungicide, and which chemicals provide the best protection.

Nematodes are soil-dwelling non-segmented roundworms, usually less than 0.5 mm (0.02 in.) long.

Informational table showing disease name, symptoms, pathogen/cause, and management of Oak diseases.

Oak leaf blister, caused by the fungus Taphrina caerulescens, occurs on most species of oaks.

Oak wilt occurs west of the Susquehanna River in Pennsylvania.

Informational table showing disease name, symptoms, pathogen/cause, and management of Pachysandra diseases.

Fungus-like organisms belonging to the genus Phytophthora are soil- or plant-borne and all are plant pathogens.

Informational table showing disease name, symptoms, pathogen/cause, and management of Pieris diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Pine diseases.

Plum pox is a serious disease of Prunus species caused by a virus.

Informational table showing disease name, symptoms, pathogen/cause, and management of Poplar diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Privet diseases.

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.

Informational table showing disease name, symptoms, pathogen/cause, and management of Pyracantha diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Redbud diseases.

A common disease of roses called black spot is caused by the fungus Diplocarpon rosae. This fungus readily attacks young expanding leaves and young canes.

The scheduling of effective disease management measures is not a simple task nor can it be standardized. The activities of the organisms that cause plant diseases are not governed by the clock or the calendar. Their activity is influenced by temperature, relative humidity, soil moisture and other highly changeable environmental factors.

Informational table showing disease name, symptoms, pathogen/cause, and management of Rose Diseases (Outdoors) diseases.

Austrian, Scots, ponderosa, mugho, red and other 2 and 3-needled pines are susceptible to the killing of shoot tips and branches caused by the fungus Diplodia pinea (formerly Sphaeropsis sapinea).

Informational table showing disease name, symptoms, pathogen/cause, and management of Spruce diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Sycamore diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Taxus diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Tulip Poplar diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Viburnum diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Vinca diseases.

Most deciduous trees and many shrubs are susceptible to a disease called Verticillium wilt caused by the fungus Verticillium. Conifers do not appear to be susceptible.

Informational table showing disease name, symptoms, pathogen/cause, and management of Walnut Anthracnose disease.

Informational table showing disease name, symptoms, pathogen/cause, and management of Willow diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Astilbe diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Coreopsis diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Viola diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Clematis diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Hosta diseases.

Informational table showing disease name, symptoms, pathogen/cause, and management of Peony diseases.

Selecting annuals and perennials for placement in the landscape as well as monitoring them for diseases and planning appropriate disease management strategies can be simplified if the key plants are known and if the key pathogens on those plants can be identified.

Note the black fruiting structures on the curved part of this tip.

There are several fungi in the northeast that are responsible for loss of needles and mortality of spruce trees. In this video, you will learn how to identify the types of spruce trees that are affected, the symptoms of the two most common needlecast diseases, and what if any treatments are available.