Postpone pruning to prevent oak wilt disease

Leaves showing signs of oak wilt diesease.
Leaves showing signs of oak wilt diesease.

By Stelle Slootmaker

The Tree Amigos


The City of Wyoming encompasses an environmental feature known as oak barrens. Located near glacial outwash areas in southern Lower Michigan, “Oak barrens likely originated when prairie fires spread into surrounding closed oak forest with enough intensity to create open barrens,” states the Michigan Natural Features website article. “Oak barrens and surrounding prairie habitat once supported a rich diversity of invertebrates including numerous species of butterflies, skippers, grasshoppers, and locusts. Mound-building ants and numerous grassland birds also once thrived in barrens and prairies.”


The article goes on to say that past degradation of Michigan’s oak barrens caused the regrettable decline of these many species.


A map showing the areas where oak wilt disease has been discovered.
A map showing the areas where oak wilt disease has been discovered.

Our City’s oak trees now face a new threat: oak wilt disease. A serious disease, oak wilt mainly affects red oak, black oak and pin oak. It can kill a red oak tree in just a few weeks’ time. In white oaks, the disease progresses more slowly.


Beetles carry the fungus that causes oak wilt from diseased to healthy trees. The fungus especially thrives on a tree that has been recently pruned or injured. The beetles become active in mid-April and stay active through mid-July. Hence, the Michigan DNR shares that you can help prevent oak wilt by not pruning or otherwise injuring oak trees from April 15 to July 15.


Help stop the spread of oak wilt disease in your neighborhood. Postpone pruning your oaks and share this advice with your neighbors. If you want to do even more to ensure that the City of Wyoming supports a healthy tree canopy, join The Tree Amigos, a citizen group supporting a vibrant Wyoming tree canopy. Like The Tree Amigos on Facebook and message or post your concerns and comments.