Knowledgebase
OAK Wilt? Otter Tale Lake, MN #873318
Asked June 16, 2024, 2:10 PM EDT
Otter Tail County Minnesota
Expert Response
Hi Maggie,
These look like some kind of gall created by insects. See this page:
https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/oak/branchesgrowths.html
There isn't a good way to control these galls except to remove any branches that have these galls in the winter. Trees can live many years with these galls.
https://hort.extension.wisc.edu/articles/deciduous-tree-galls/
https://forestrynews.blogs.govdelivery.com/2018/05/04/phomopsis-galls/
Hope this helps. Thanks.