Weird growth on leaves of Maple tree

Asked May 29, 2020, 8:34 AM EDT

I live in Glenwood, Howard county, and this morning I noticed strange growth about 1/4 inch in height growing on the leaves of our maple tree. It seems to be all over the tree. What can I do about this. I took photos Thank you for your help. Eileen

Howard County Maryland

1 Response

Hi - These little protrusions on the leaves are called spindle galls. They are formed as a reaction to feeding by tiny mites. These and other galls are not unusual to see on maples. The damage may be undesirable aesthetically, but the galls do not do major harm to the plant. We do not recommend any form of treatment.

Here are links to more information about galls in general and on maples specifically.
https://extension.umd.edu/hgic/topics/shade-tree-galls
https://ohioline.osu.edu/factsheet/ENT-60

Christa