How can I help? I have a beautiful sugar maple that I think has verticillium wilt.

Asked May 26, 2018, 11:51 AM EDT

Hi, I wrote last year about my sugar maple and it still has white plack type spots on it's bark. I think it has verticiullium wilt. Is there anything I can do to help this tree, slow down the process? I do not want to lose this tree, it provides lots of shade and is beautiful. Thanks, Michelle

Ramsey County Minnesota

1 Response

Sorry for not responding earlier. I am out of town teaching a class.

Verticillium wilt has no outward signs, only symptoms that that fungus has infected and is damaging the tree. The outward symptoms are single branch leaf wilting, turning brown, and clinging to the branches. Removal of the branch and scraping off the bark to see if there is brown to black streaking of the wood immediately under the bark and/or any dark dots in the end cut of the symptomatic branch are the field diagnostic clues.

White patches on the bark are usually early stages of lichens. Completely, 100% harmless. Without a photo that is representative of your tree symptoms, any email diagnosis could be accurate or completely off-base. If you are concerned about the health of the tree, you should hire a diagnostic professional to visit the site, take samples and pay for submission to the U's Plant Disease Clinic.