Oak Wilt in Northern Michigan

What is Oak Wilt?

Oak wilt is a lethal disease caused by a fungus (Bretziella fagacearum). It causes untimely death of oak trees and spreads extremely quickly both below and above ground.

How do I spot it?

Infected trees usually have abnormal leaf loss-think your oak dropping nearly all its leaves mid summer. These leaves experience color loss as well. Underneath the bark, large areas of fungal mats known as pressure pads appear as well.

How can I avoid it?

Observe a no prune period with your Oak Trees. This includes weed whipping near them, children picking at bark, hanging anything on oak trees, etc. as even the smallest injury can allow the disease in. The no prune period is from April 15-July 15. If pruning occurs outside of these dates, it is still is wise to ‘paint’ the wound on the tree where you pruned, as beetles-who spread the disease, can find their way onto the exposed tree within 10 minutes. Along with observing the no prune period, be sure to not move firewood from location to location. Moving firewood can cause the spread of not only oak wilt, but various other tree killing diseases and infestations.

What do I do if my trees have it?

It is vital that Oak Wilt is properly diagnosed. There are many different issues that could cause symptoms similar to what you see with Oak Wilt. Calling a professional to look at your trees is extremely important, as if it is Oak Wilt, it needs to be dealt with immediately before it spreads. If an oak tree is injured (during a storm or from improper pruning), call someone right away as the disease can attack and spread in under 24 hours.