Occurrence: During active growing season when insect pressure exists. Leaf galls are bumps and deformations usually resulting from insects feeding on the leaves. The gall is the plant’s response to the irritation. By the time you see the gall, the insect has moved on. The gall is not going to go away until the end of the season when the tree loses its leaves. Galls won’t usually kill a tree, but they may cause early leaf drop. A healthy tree will send out new growth and recover.
Since the damage occurred before the gall formed, treatment is not usually recommended. To help reduce future gall development, spray your trees starting in early spring and periodically throughout the season to reduce insect pressure. We recommend four sprays each season. Contact us for treatments. If you choose to treat yourself, make sure you identify the insect for which you are spraying and follow label instructions particularly relating to timing, number of treatments, and rates.