Oak Wilt

Environmental Effects | Prevent the Spread

Oak wilt is a fungal, vascular disease that quickly kills oak trees (particularly red oaks) by effecting their ability to transport water. Symptoms include leaf-fall in summer and second-year fungal “pressure pads” forming on trees underneath the bark. Spores are spread by native insects and the infection can move to other oaks through interconnected roots.

Currently, positively identified occurrences are concentrated on the western side of Oakland County. Do you suspect you that your oak trees might have this disease? Report it on the MISIN website, through the smartphone app, or to the Oakland County CISMA immediately! Please include photos to help with ID verification.

michigan.gov/dnr species profile

More pictures

Environmental Effects

This disease can kill many oak trees, which are an important source of food for many wildlife species. Oaks also provide shade, oxygen, and other ecosystem services.

Prevent the Spread

Wait until late fall or winter to prune to your oak trees because the beetles that spread the fungus are attracted to fresh cuts of trees. If you need to prune, cover wounds immediately. Additionally, don’t move firewood as this can transport forest pests.