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Growth on Purple Ash Tree #876273
Asked July 08, 2024, 8:34 AM EDT
Hello, We live in northern Colorado and our purple ash tree has a growth on it that we are concerned about. The growth looks like clumps of brocolli. It is everywhere on the tree. Some clumps are large and others are small. Any ideas on how to remove it or should be be concerned? We don't see any mites visible. Thank you
Weld County Colorado
Expert Response
Hello, Denise. Thanks for contacting Ask Extension. My name is Kat, and I am helping you with your question today.
From your description, the growths you are seeing could be ash tree flower galls. Please see the photo in the link attached below.
If this does not resemble the growth, please send us a photo so we can research further.
The galls are not harmful to the tree, but definitely unsightly. The attached link provides more discussion of this gall.
Since the galls are not harmful to the tree, no treatment is recommended, since timing when to spray any insecticide is tricky, and it could be harmful to beneficial insects.
Is you have any further questions, or want to send a photo to confirm this is what your tree has, please do.
Again, thanks for contacting Ask Extension.
Kat