Oak wilt

Asked October 4, 2018, 12:30 PM EDT

We have a Red Oak tree that likely has Oak Wilt. There is another about 10' away that looks fine but seems might not be worth effort due to the close proximity to the infected tree. My main concern is another group of Red Oaks maybe 40' away. I have Rainbow Tree Service coming out today. I'm sure they'd like to sell me lots of protection. Not sure how to understand how close a tree needs to be to be at risk. If I was to treat them, how many years I'd need to do it. I'm guessing this is expensive and would rather keep $$ in my pocket! If you are getting this email today, Thursday October 4 I may need to make a decision to treat YET TODAY as they are stopping services for the season.. I'd appreciate any advice you can give. Eric Anderson 12112 Glendale Lane Minnetonka, MN 612-325-6777

Hennepin County Minnesota

1 Response

If you don't already have a confirmed diagnosis of oak wilt, you can send a sample to the University of Minnesota. The instructions are located at the website below. https://pdc.umn.edu/submit-sample If you do have oak wilt in red oaks, the recommendation is to remove affected trees and have the roots cut to protect any nearby unaffected oaks. 40 feet could still be within the possibility of distance for root grafts to occur and spread the disease. The distance needed between trees to avoid the underground spread of disease by grafting is affected by many different factors (tree type, size, terrain , etc). There are also fungicide treatments that can be given to trees every 2-3 years to prevent uninfected trees from getting oak wilt. The websites below have a great deal of additional information that will hopefully help you make the difficult decisions for what to do with your currently healthy trees. https://extension.umn.edu/plant-diseases/oak-wilt-minnesota#how-can-i-stop-the-spread%3F-1258962 http://learningstore.uwex.edu/Assets/pdfs/G3590.pdf A certified arborist is recommended for management of oak wilt. See here for information about hiring an arborist. https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional