Healthy Oak Tree removal during high risk oak wilt season
Asked April 10, 2019, 4:21 PM EDT
I have 3 healthy Oak Trees to remove. They do not have oak wilt. I plan on cutting them down completely to the ground, cutting up the logs for firewood, and chipping the branches. Now that high risk oak wilt season has started;
1. Do I have to wait until fall even though the trees are being killed anyway?
2. Would the oak wilt beetle attack my cut & stacked wood, and would the fungus grow on the dead logs?
3.It's snowing now, does the snow give a temporary safe period for pruning?
Thank you for the question. Extension recommendations are to wait until at least mid July through late October for any kind of oak tree work and that includes tree removal. If possible, the best time when there is no risk is November through March. Concerns can be put to rest if you wait to remove the trees until November 1. Oak wilt is easy to prevent but hard to treat. I can't find specific research based publications that directly discuss potential oak wilt issues and felled, healthy trees during the high risk time of the year so I'm going to summarize what I think the main points are.
- You live in a County with known oak wilt.
- Oak wilt can spread amazingly fast, within 15 minutes and up to a few days of a fresh cut due to beetle attraction. It is also spread through root systems from other oaks nearby. Even though your trees look healthy, it's possible that their roots may be infected if there are other oaks within about 50 feet from yours that have infected roots. It may be safest to assume they are infected and proceed accordingly if you decide to remove them now.
- When the wood is freshly cut, it may attract beetles. This might not be a problem for you personally but could cause spread of the disease to other oak trees.
- The fungus might start to grow on the logs but it doesn't tolerate extremes of temperature nor does it live on dried, cured wood. Some publications advise covering the logs with clear or black plastic, 4 mm thick and burying the edges under the soil so that if beetles do find the fresh wood, they won't be able to move on and transmit the disease. The heat that builds up under the plastic would kill any fungus that starts to grow before the wood dries out. It is advised that the wood remain covered until next September if you cut now. This is advised for infected logs but the research isn't so clear on healthy wood. If you wait to cut until the safe period, this isn't necessary.
- If you prune before the safe season, you should paint the stumps with shellac or paint.
Read more about oak wilt in our publication on oak wilt in Minnesota: https://extension.umn.edu/plant-diseases/oak-wilt-minnesota
Another option for advice would be to contact a licensed, certified arborist. Learn how to choose a reliable one: https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional
At this time of the year, our weather can change drastically so I don't think we can assume that the brief chill/snow right now means that it's safe. Insects are amazingly capable!
Thank you for contacting Extension.