Nectria Canker

Nectria canker is a common and potentially lethal disease that affects many species of trees and shrubs. This factsheet describes what nectria canker looks like and management options.

Southern Blight

Southern blight is a lethal fungal disease that is most common in the tropics and subtropics, but can cause problems in temperate locations like Wisconsin during periods of warm, moist weather. Learn more here.


Tatters is a leaf disorder affecting primarily trees in the white oak group. This factsheet has more information about what Tatters is and symptoms to watch for.

Tubakia (Actinopelte) Leaf Spot

Tubakia (Actinopelte) leaf spot is a common late-season leaf disease of oaks, especially those in the read oak group. Learn symptoms and management in this factsheet.

Crown Gall

Crown gall is the most widely distributed bacterial disease of plants in the world. This factsheet describes what crown gall looks like and how to avoid problems with this disease.

Butternut Canker

Butternut canker is a fungal disease that affects native butternut trees, causing multiple cankers on trunks and branches, eventually killing the trees. Learn to recognize this disease in this factsheet.

Black Spot

Black spot is a common and potentially serious leaf spot disease affecting many types of roses. Learn about symptoms and management in this factsheet.

Dead Man’s Fingers

Dead man’s fingers is the name of a mushroom-like fungal growth that can be found at the base of dead or dying trees and shrubs, as well as wood objects. Learn about this distinctive fungus in this factsheet.

Bacterial Canker

Bacterial canker is a common and sometimes lethal disease of trees in the genus Prunus including cherry, plum and peach. This factsheet describes symptoms and management of bacterial canker.

Fire Blight

Fire blight is the most destructive bacterial disease affecting plants in the rose family, including apple, pear, crabapple, hawthorn, cotoneaster, mountain ash, quince, rose, pyracantha, and spirea. Learn more here.

Downy Mildew

The downy mildews are a group of fungal diseases that cause destruction of the leaves, stems, flowers and fruits of many plants, including grapes, cucumbers and roses. Learn symptoms and controls in this factsheet.

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