Dan Martin / news@WHMI.com

The Michigan Department of Natural Resources is advising tree owners to prune their oak trees now during cooler weather.

With most of the leaves having fallen to the ground and temperatures cooler, the Michigan DNR says now is a prime time to prune oak trees, which can be infected with oak wilt fungus if they are pruned during the high risk period between mid-April and mid-July.

Simeon Wright, a DNR forest health specialist says "Beetles that can carry disease from tree to tree are not very active now, and the trees are not vulnerable to infection" at this time.

Wright says the bugs are attracted to fresh bark damage or wounds where limbs have been removed. He also adds that oak wilt can spread from cut wood to living trees and advises that wood from oak trees that may have been infected be covered with a plastic tarp with the edges buried underground to prevent access by the disease-spreading insects.

Ensure the tarp remains intact for 6 to 12 months until the bark sloughs off. This will kill the fungus and prevent its spread to healthy trees.

Oak wilt, identified in the 1940's is widespread across Michigan's lower peninsula and along the Wisconsin border with the U.P. Red oaks are most susceptible, and can die within weeks of infection. Affected trees will wilt from the top down, rapidly dropping leaves.

If you suspect a tree has oak wilt, report infections at Michigan.gov/ForestHealth.