NORTHEAST WISCONSIN – The Wisconsin Department of Natural Resources is urging homeowners and landowners to keep a close eye on their oak trees as oak wilt, a destructive fungal disease, continues to threaten forests and residential properties across the state.
DNR Forester Kylie Husman says the disease is spread by sap-feeding beetles that are attracted to fresh wounds on oak trees.
“If you have an oak tree that is wounded, it starts to produce sap, and the beetle is attracted to that sap,” Husman explained.
Once the fungus enters a tree, one of the earliest warning signs often appears high in the canopy. Husman says property owners should watch for wilting leaves and dying branches near the top of the tree.
She encourages anyone who notices those symptoms to contact a forestry professional or the DNR before the disease has a chance to spread to nearby oaks.
One of the most effective ways to prevent oak wilt is by carefully timing when oak trees are pruned or removed. Husman says tree work should only be done during the months when the beetles that spread the disease are least active.
“If you are going to prune your oaks or cut down your oaks, only cut them in the ‘ER’ months, September, October,” Husman said.
The DNR says limiting pruning to the fall months greatly reduces the risk of attracting beetles carrying the oak wilt fungus.
Husman also recommends inspecting oak trees after severe storms for broken limbs or fresh wounds. Those openings can provide an entry point for the fungus if left untreated.
State forestry officials say early detection and preventative care remain the best defenses against oak wilt, helping protect both individual trees and Wisconsin’s valuable oak forests.
Comments