White Birch

Asked July 8, 2019, 10:08 AM EDT

North Muskegon, Michigan. About a 5 year old white birch is growing a white powdery mildew. What is this mildew and how do we treat it?

Muskegon County Michigan powdery mildew white birch

1 Response

This doesn't appear to be a disease but rather an insect! This is most likely an aphid, probably of the Hamamelistes genus. Control with a systemic could be an option but could be harmful to bees. If the tree is small they can be sprayed of with water. Treating may not be necessary. Check out the following links:
https://www.clemson.edu/extension/publications/entomology/turf-ornamental/river-birch-aphid-to17.html
https://bugguide.net/node/view/356289
http://hyg.ipm.illinois.edu/pastpest/200510e.html
I hope this helps,