Remember – to protect oak trees and help prevent oak wilt, the Wisconsin Department of Natural Resources advises people to avoid pruning oaks on their property from April through July. Any tree damage during this time creates an opening that exposes live tree tissue and provides an opportunity for the oak wilt fungus to invade and establish itself in the tree.
Since trees are growing so much in spring, their energy reserves are low, making them more vulnerable to contracting the oak wilt fungus. All it takes is a beetle carrying the spores to land on an open wound for the tree to get infected. Trees can become infected in as little as fifteen minutes after being damaged.
Oak wilt is found in all Wisconsin counties except Ashland, Bayfield, Calumet, Door, Douglas, Forest, Iron, Kewaunee, Manitowoc, Price, Sheboygan and Taylor counties.