Map Shows Where Oak Wilt Disease Has Been Found in Michigan
This is a dangerous time of year for oak trees in Michigan. Now through July 15 is when oak wilt disease can be transmitted to healthy oak trees.
See where the disease has been found in Michigan and how to protect your trees.
The Michigan Department of Natural Resources says oak wilt mainly affects red oaks, including northern red oak, black oak and pin oak. Red oaks often die within a few weeks after becoming infected. White oaks are more resistant.
The best way to prevent oak wilt is to not prune or injure your trees from April 15 – July 15. New oak wilt sites have been traced to tree-climbing spikes, rights-of-way pruning, nailing signs on trees and accidentally removing tree bark.
If an oak is wounded, the DNR advises covering the wound immediately with either a tree-wound paint or a latex paint to keep beetles away.
Once an oak is infected, the fungus moves to other red oaks through root grafts. Oaks within approximately 100 feet of each other – depending on the size of the trees – have connected or grafted root systems. Left untreated, oak wilt will continue to move from tree to tree.
A new map from the Michigan DNR shows where oak wilt was found in 2016.