eXtension

oak tree with raised red growths

Asked July 30, 2020, 2:39 PM EDT

We have an oak tree that is about 7 years old. Recently it has developed raised red growths on the leaves. The leaves also seem to be becoming damaged. Any advise would be appreciated. Thank-you, Rick and Debbie Muncy Plymouth, MI

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Wayne County Michigan

1 Response

Hello Rick and Debbie,

Those growths on the leaves of your red oak are galls probably caused by cynipid wasps. More than 800 species of the cynipid wasp lay their eggs on oak leaves. The insect causes abnormal growths, called galls.

This question was answered previously by an MSU Entomologist which I am attaching.

https://ask.extension.org/questions/419681

He is referring to a different gall, but the same information applies to the ones that you are seeing.

I hope this answers your question.

Thank you for contacting Ask an Expert.