Oak Wilt Prevention – It’s up to you and me!
Oak wilt, a non-native vascular wilt fungus that is fatal to red oaks, is present and spreading in Northern Michigan. Symptoms of oak wilt include the rapid loss of leaves, typically in mid-summer, and the slow progression from infected red oaks to adjacent healthy red oaks from one year to the next. Oak wilt once established spreads underground through the interconnected root systems of red oak trees. New infections can also begin when beetles spread spores from infected trees to healthy trees that are pruned or injured during the spring and early summer. A newly infected tree will lose all of its leaves in mid-summer.
To help prevent new infections, property owners should refrain from doing any oak removal or pruning between April 15th and July 15th, when beetles move spores from trees killed last year. The Nitidulid “picnic” beetles will pick up fungal spores and transfer them onto a freshly cut oak 1 to 1 ½ miles away. It is critical to not injure any oaks or create any way for the fungus to enter the vascular system of the healthy tree during this time. In addition, it is important not to move any firewood from trees that have been killed by oak wilt because this can also transport the disease to unaffected areas.
Benzie County has several confirmed oak wilt sites and treatment practices are working toward containing the spread. Other surrounding counties have been battling oak wilt since the 1980s, but vigilance is needed everywhere to keep loses from oak wilt to a minimum. The Forestry Assistance Program in ten Northwest Michigan Counties including Benzie, was awarded a DNR Michigan Invasive Species Grant to help private landowners cover the cost of oak wilt control treatments.
Residential treatment applications can be confounded by underground infrastructure, driveways, walks, gardens, property lines, and many other factors. However, high value residential oaks may be treated with an injected registered chemical that protects individual trees. The treatment needs to be repeated every two years. For homeowners, the injection costs for yard trees might be a viable option. Prevention is far cheaper than treatment.
Oak wilt is here to stay in Michigan. Human activity will most likely move the disease into previously affected stands as time goes on, however, oak wilt can be successfully managed and the oak forest resource will remain a part of our forested landscape.
The DNR and Conservation District Foresters are trying to confirm and document the extent of oak wilt in Michigan. If you would like more information, or suspect you may have oak wilt and would like it confirmed contact the Michigan DNR Forest Health Program at (517) 284-5895 or DNR-FRD-Forest-Health@michigan.gov or the Leelanau, Grand Traverse and Benzie Conservation District Forester, Kama Ross, at (231) 882-4391 or firstname.lastname@example.org.
Oak Wilt Pest Alert: