Growth on oak tree - Ask Extension
We have scattered brown/black round, hard growths on our huge oak tree. Can you tell us what they are and what we should do about them. We sure do not...
Knowledgebase
Growth on oak tree #863165
Asked April 02, 2024, 4:13 PM EDT
We have scattered brown/black round, hard growths on our huge oak tree. Can you tell us what they are and what we should do about them. We sure do not want to lose this tree.
Pine County Minnesota
Expert Response
Hi Gail,
You have Oak Gall which I know looks alarming but it's a pretty harmless condition caused by tiny insects.
https://extension.psu.edu/galls-on-oak
There isn't really anything you can do about them but they won't kill your tree.
http://www.minnesotaseasons.com/Insects/oak_rough_bulletgall_wasp.html
Sally Granath
Saint Louis County MG
