Oak wilt, a deadly disease that affects oak trees, has been found for the first time in Ashland County.
The DNR detected the disease in wood samples from a red oak tree in the town of Gordon.
"There is always the risk of oak wilt spreading into new and relatively uninfested areas in northern Wisconsin, such as Ashland County, so it's always best to practice oak wilt prevention wherever possible to significantly reduce that risk," said Paul Cigan, DNR forest health specialist in Hayward.
The disease strikes in mid- to late summer, leaving branches with wilted leaves and leaves on the ground at a time when you wouldn't expect to see that.
Oak wilt is commonly found in the southern two-thirds of the state and is creeping north.
Although oak wilt has been identified in 66 of Wisconsin's 72 counties, most of northern Wisconsin is still free of oak wilt, so it is important to prevent the spread of this disease.
Avoid pruning or injuring oak trees from April through July. If an oak is pruned during that time, seal the wounds with a water-based (latex) paint or pruning sealer.
Getting your firewood locally will also help prevent the spread of oak wilt.
The University of Wisconsin's Plant Disease Diagnostic Clinic (608-262-2863) can help verify the presence of oak wilt. A sample must be sent to the clinic, and a small fee is charged for the service.
Additional information is available on the DNR website covering oak wilt and firewood guidelines.
