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What is on buttonbush leaves #947453

Asked October 21, 2026, 1:38 PM EDT

Is it harmful to the shrub? Is there something I should do to prevent it next year?

Oakland County Michigan

Expert Response

Hello
These are leaf galls, most often caused by tiny mites. They are a cosmetic problem and do not harm the plant.
You can rake up and destroy the leaves this fall or dispose of them in the trash. Do not compost them.
This can help minimize the population that overwinters in your area.
Here are more details
https://www.canr.msu.edu/news/velvet_galls_caused_by_tiny_eriophyid_mites

https://yardandgarden.extension.iastate.edu/article/2009/6-10/erineum.html

Thank you for your question! Laura S. Michigan State University Extension Advanced Master Gardener Volunteer You may also contact the toll free MSU Extension lawn and garden hotline at 1-888-678-3464 with your gardening questions or visit www.migarden.msu.edu for Smart Gardening resources. Replied October 21, 2026, 1:54 PM EDT

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