Galls form on roots and stems, especially at the root collar – the junction of roots and stem. Young plants with large or numerous galls tend to be stunted and predisposed to drought damage or winter injury. Galls continue to enlarge as plants grow and can disfigure woody stems.

How do galls affect plants?

Galls usually form during the accelerated growth period of new leaves, shoots and flowers in late spring. Insects or mites damage plants by chewing on them and their salivary secretions (spit) cause plants to increase production of normal plant growth hormones. … These abnormal cell growths are called galls.

Do galls kill plants?

Insect & Mite Galls Most plant galls are caused by mites and wasps. The tissue growth is the result of irritation caused by the feeding of the insect or by powerful plant growth-regulating chemicals injected by the insect during egg laying or feeding. … Generally speaking, most galls do not seriously harm the host plant.