strange growths on leaves

Asked May 27, 2014, 11:43 AM EDT

I noticed these strange growths on some of the leaves of my plums trees. This is the first year that I've noticed them. The trees were planted 5 years ago and last year was the first time they produced mature fruit.

Story County Iowa

1 Response

The strange growths on the plum leaves are galls. Galls are abnormal growths induced to form by small insects or mites. Fortunately, galls do not cause serious harm to trees. The damage is mainly cosmetic. Treatments are not necessary.

Additional information on galls can be found at the following website. http://www.extension.iastate.edu/publications/ic417.pdf