Damage to my maple trees

Asked July 30, 2020, 4:53 PM EDT

Could you please tell me what is damaging the leaves on my maple trees. It is very extensive on both of my trees. See attached pictures. Will it damage or kill the tree? Is there something I should be spraying on the tree?
They are Autumn Blaze Maples and about 4 inches in diameter.

Thank you

Anoka County Minnesota

1 Response

These are galls, specifically maple bladder galls:

They are caused by the reaction of the tree to small mites feeding on the leaves. While you think they are extensive, there is still substantial photosynthetic leaf surface left, and they are not harming the tree. Nothing needs to be done about them.