This year’s cool spring weather has caused people to wonder if the oak harvesting restrictions that usually begin on April 1 (south of the tension zone) or April 15 (north of the tension zone) might be pushed back due to unusually cold temperatures. The simple answer is no. Even during unusually cold springs, consistent messages about preventing the spread of oak wilt disease apply – “Stop pruning in April” and “Avoid harvesting in April (south of the tension zone)”. Delivering the same messages at the same time every year helps ensure that the public protects Wisconsin’s oak resource.
That said, the Wisconsin DNR’s oak harvesting guidelines allow flexibility at the stand level, if landowners/property managers and other affected parties (foresters, loggers, etc.) all agree on modifications based on local conditions. For example, “unusual weather patterns in early spring” is listed as one of the allowable modifications in the DNR’s oak harvesting guidelines.
When experiencing an unusually cold spring, landowners, property managers and other affected parties should agree upon how long to extend harvesting based on weather, their comfort with risks involved, and relative importance of completing the harvest. When harvesting deadlines are extended, it is important to consider that oak stumps are susceptible to oak wilt for up to 72 hours after cutting.
Justification for using the “unusual weather patterns in early spring” modification needs to be documented in the cutting notice/report form.
Kyoko Scanlon, DNR Forest Pathologist