Intro to Oak Wilt

What is oak wilt?

Oak wilt is a fungal disease that affects oak trees. As the name implies, oak wilt causes leaves of affected trees to wilt and turn brown. It is fatal for red oaks, including northern red oak, pin oak, scarlet oak and black oak. White oaks are affected but may survive. The incidence of oak wilt has greatly increased in Michigan in recent years. For more detailed information about oak wilt, CLICK HERE.

How is oak wilt spread?

Oak wilt is spread from infected to healthy trees in two ways:

Through root systems from adjacent infected trees.
By certain kinds of beetles, which carry spores between infected trees, logs or even firewood, and fresh wounds (such as pruning cuts) on unaffected trees.

The activities of people, such as pruning during vulnerable times, or moving infected firewood, can cause new infections. For more information on how oak wilt is spread, and the life cycle of the beetle and fungus, CLICK HERE.

How do I know what kind of oak tree I have?

Oak trees in Michigan can be divided into two main groups: red oaks and white oaks. Generally, red oaks have pointed leaf lobes and white oaks have rounded leaf lobes. The red oak group is more susceptible to oak wilt. For more information on identifying oak trees, CLICK HERE.

Management - “What do I do with my tree that has oak wilt?”

Oak wilt is a serious threat to oaks in Michigan's landscape: forests, woodlots, parks, suburban neighborhoods, urban properties; basically anywhere oaks grow. A variety of management strategies can be employed to minimize the development of new infection centers and to combat existing infections. However, the most effective way to protect oak trees is prevention - by avoiding injury to trees when beetles are active, and by separating roots between infected and uninfected trees. For more information on prevention and treatment options, CLICK HERE.

If you own oak trees, or if your work requires you to prune or harvest oak trees, you can prevent the spread of oak wilt by following certain basic precautions. For more information, click on your area of interest: TREE OWNERS UTILITIES MUNICIPALITIES ARBORIST AND LANDSCAPING FIRMS FORESTERS TIMBER HARVESTERS