Horse Chestnut Galls in Buffalo, NY

Asked June 14, 2016, 5:06 PM EDT

My Horse Chestnut is situated in a residential city neighborhood in Buffalo, NY. What are the possible reasons for bark disrupting galls? They have occurred only on the branches of the tree, though I notice some bulging of the trunk now that I have a photo. I note no bleeding or rustiness on the trunk or near these wounds on the branches. In 2015 a tree service diagnosed ‘Stem Blight’ and sprayed the trunk bark in mid- and late- spring with ‘Basal Bark Treatment’. In 2016 another tree service diagnosed target cankers and advised no treatment other than proper maintenance including deadwood pruning, fertilization and watering during dry periods. Can you clarify what’s happening to my tree and what’s best to do about it? Thank-you very much, Phyllis R.

Erie County New York

1 Response


Realistically from just a photo and your description, one cannot diagnose your tree's problems. Galls can be caused by insects or disease. There usually is no recommended treatment. Hopefully one of the two companies you hired had a licensed or certified arborist look at your tree. If so, I would tend to listen to what that person says. Perhaps they can bring some samples to a plant diagnostic lab so if there is a disease, it could be identified. Keep in mind that horse chestnuts in general are susceptible to a variety of disease and insect problems including leaf spot, wood rot, anthracnose, canker, scale, borers etc. Your best bet would be to find a good licensed arborist and follow their advice.