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Oak Wilt

Invasive Species in Michigan

What is it?

Oak Wilt is on Michigan's Invasive Species watch list. It is an exotic disease that devastates red oak trees. It can also affect white oak trees, but they have more natural defenses.

An infected tree will often drop its leaves suddenly in the summer or there may be browning leaves. They may be completely brown or partially green. Often times, the leaf tips will be brown but the leaf base will remain green.

Impacting Local Habitats

Once a red oak tree is infected, there is no treatment to save it and it will die. Once a tree is confirmed as having oak wilt, there are treatments to protect the surrounding trees & slow the spread of the disease. If a group of infected trees goes untreated, the disease could spread and wipe out an entire neighborhood or forest.

What to do

Do NOT prune oak trees during the growing season. If you must prune oaks, do not do so between April 15 and July 15. Do NOT move firewood.

If you suspect Oak Wilt, take pictures and report it to the Department of Natural Resources Forest Health Division by calling 517-284-5895 or emailing: