Oak wilt disease: 373 infections identified in southeastern Minnesota

Photo interpretation of color infrared photography taken last September has been completed and transferred to topographic maps. Some 373 oak wilt infection centers have been identified in several locations across southeastern Minnesota that have known to have a history of oak wilt disease and were targeted in the photography. Below is a summary of the survey.



Number of
infection centers

Red WingGoodhue59
Wabasha-South Wabasha32
Winona-North Winona21
Winona-South Winona6
St. Charles Winona17

Financial assistance will be available this year in southeastern Minnesota to suppress oak wilt. Southeastern Region and Area Foresters will attempt to contact all of the affected landowners early this season to advise them of the Community Forest Health Grants. Any landowner may apply to take part in suppression program. To take part in the program, landowners should contact their local DNR Area Forester. The forester or his representative can complete a field inspection to determine if the oak wilt disease is present and if control practices are feasible.

The symptoms of oak wilt in red oak trees include rapid wilting of affected leaves and branches, wilting from the top down with the wilting leaves changing from dull green to brown. Symptoms of oak wilt in bur oak trees appear only in part of the tree's crown. Oak wilt is not as common in bur oak trees, but it does occur. The diagnosis for oak wilt can usually be done in the field or by laboratory analysis. We expect oak wilt disease to begin showing up early this year by mid-June due to the early spring.

If the field inspector determines that oak wilt is present, the landowner can apply for the cost share funding through the local Soil and Water Conservation Offices (see listed counties in table, above). Once approved, the landowner will be free to contact a qualified vendor for a cost estimate on controlling the disease. Landowners will be eligible for reimbursement of up to 50 percent of the approved cost after the control project is complete.