Environmental Effects | Prevent the Spread
Oak wilt (MSU ext.) is a fungal, vascular disease that quickly kills oak trees (particularly red oaks) by affecting 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 Oakland County CISMA immediately! Please include photos to help with ID verification, but generally a site visit is necessary to attempt to reveal “pressure pads”/fungal mats under the bark or recently killed trees.
Environmental Effects
This disease can kill many oak trees, which are a dominant canopy tree species and 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 using a tree wound dressing as bark beetles (Nitidulids) can quickly find fresh tree wounds. Additionally, don’t move firewood as this can transport forest pests. Burn firewoood where you buy it/harvest it.
MI DNR Oak Wilt Map
View the reported cases of Oak Wilt near you.
Learn More
Michigan Oak Wilt Coalition informational brochure
MSU Extension: In-depth on Oak Wilt and Michigan Forests
USDA NE Region How to Identify, Prevent, and Control Oak WIlt
Find out about other invasive forest pests in our brochure!