By Jessica Mathews /

Spring often signifies yard clean-ups and cottage re-openings but it’s also the highest risk period for Oak Wilt infections.

May is Oak Wilt Awareness Month across Michigan and the Michigan Oak Wilt Coalition is working to raise awareness and highlight actions that people can take to stop the spread. Campaign Co-Chair Ruth Dorando Marcy is an MSU Extension Master Gardener and Program Assistant for Oak Wilt Educational Outreach. She’s also with the Michigan Oak Wilt Coalition, which is a partnership of concerned private, non-profit and governmental organizations.

Oak Wilt is a fungal pathogen that basically blocks the vascular system of a tree, preventing the flow of nutrients and resulting in the tree beginning to wilt

The disease started in the early 1900s but is becoming more prevalent, especially in the Upper Midwest. Dorando Marcy says that’s because there are so many oak trees, and many are in the Red Oak family, which are more vulnerable to the disease. She tells WHMI it’s important to understand when the right time to prune is, what to do if a tree gets wounded during the high-risk period and what to do if there is an infection to make sure it doesn’t spread.

The disease is spread two ways; the first is from a fresh pruning cut or a wound caused by a hit from a lawnmower or storm damage. Dorando Marcy says the wound attracts sap beetles that carry spores and deposit those into the fresh wounds, infecting the tree. The other happens once a tree is infected in that it can pass the spores through the root system to other trees, which then basically becomes an epidemic.

Pruning should happen ideally in the winter and the high-risk period from April through July should be avoided altogether. If there is a wound or unavoidable pruning, then Dorando Marcy says it needs to get sealed so the beetles can’t infect the tree.

The Coalition received a grant from the U.S Forestry Service and the Michigan Department of Natural Resources, which allowed for the printing of educational materials and plastic bags to get the message out that are available at MDOT welcome centers. There’s also a billboard on northbound US-23, near Whitmore Lake.

More information about Oak Wilt and prevention is available via the attached press release and web link.

Top photo - Left to right: Oak Wilt Awareness Co-Chair Julie Stachecki and Ruth Dorando Marcy with a Red Oak that is more than 200 years old.

Bottom photo - Oak Wilt awareness billboard