Warm weather brings concern for oak trees

Early warm weather has Wisconsin tree experts worried a fungal disease known as oak wilt that kills red oak trees could come sooner this year. The disease typically arrives sometime in April, but with unseasonably warmer temperatures it's likely to have already arrived across much of the state, the Department of Natural Resources said. The department is urging homeowners and landowners to hold off on pruning oaks until the end of July, as any such disturbance allows the oak wilt fungus, transported as spores by sap beetles, to invade a tree. "Even a half-hour can be enough time for beetles that transmit the disease to land on a fresh wound and infect your tree," Kyoto Scanlon, a forest pathologist with the DNR, told the Milwaukee Journal Sentinel. The disease can also pass through the root system, she said, and unless treated is usually fatal. Oak wilt disease has killed tens of thousands of trees in the state, she said. "It's pretty much a death sentence."