Forester warns of spring oak wilt dangers

The spring is a time for plant growth and gardening. It also is the start of a different season –oak wilt.

“The most dangerous time of year for oak wilt is April 15 to July 15,” Alcona Conservation District Forester Eric Brandon said.

Oak wilt is a vegetational fungus that attacks oak trees and is 100 percent deadly, Brandon said. It is a spore pad and it smells like Juicy Fruit gum, he said. The smell attracts beetles that feed on tree sap.

“If someone prunes an oak at a certain time of year the beetles can smell the sap from a mile away. If they visited a tree with the the spore pads they deliver the fungus for the new tree to be infected,” he said.

The insidious part about oak wilt is the second way it spreads is underground, he said. He said the fungus spreads underground because oaks exchange nutrients through their root systems.

“It’s like a ripple effect in slow motion. It will not stop until it runs out of oak,” Brandon said.

Michigan State University senior academic specialist Dr. David Roberts said the disease is similar to Dutch elm and ash borer.

“Unfortunately there are two major oaks: red oak and white oak,” Robers said. “Red oak family is especially susceptible. It’s regarded as a loss once infected. Nothing to do about it. It dies about in about one to two months.”

Once it starts the leaves of the oak will begin to turn brown, and it will spread to each leaf in the tree. Brandon said the spread will be fast and dramatic.

Once it’s found the trees can’t be saved, but there are methods to try and stop the spread.

“Underground it takes some pretty invasive methods. One is to trench five to six feet deep between infected trees and healthy trees the other method is to inject healthy trees with a fungicide. Both methods can become quite costly,” he said.

The infected dead trees can be cut down and used for firewood, Roberts said. However, that firewood should not be moved from the area it’s located.

For example, if a tree is infected and cut down it can be used for firewood at that home, but should not be moved to someone’s lake home, cabin or camp site somewhere else.

Trees can be damaged a multitude of ways Roberts said. They can be nicked when people mow lawns, during disc golf, or after strong storms.

Roberts said if a tree is damaged people can ask an arborist to come to their home, make a clean cut and seal the cut.

To learn more about oak wilt visit the Michigan Oak Wilt Coalition at

Jordan Spence can be reached via email at or by phone at 358-5687.