Common Diseases: Galls

• Categories: Common Diseases Common Problems
• Last review date: 2026-03-28 10:04

Biology

A gall is a swelling or overgrowth produced on a plant as a result of infection by certain pathogens or physiological stress. Galls may be found on leaves, stems, trunks or roots.

They can be caused by fungi, bacteria, nematodes, insects, or physiological problems. To determine the cause of a plant gall, cut the gall open and examine for insect chambers and signs, such as frass and insect parts.

Check diagnostic references for the common gall problems associated with that particular host plant.

Management Options

See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.

Non-chemical Management

Select non-chemical management options as your first choice!

• Remove and destroy galls if the causal organism can spread to other susceptible plants.

Chemical Management

IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides, visit Home and Garden Fact Sheets | Pesticide Resources and Education Program | Washington State University. Also visit Pacific Northwest Pest Management Handbooks.

• Determine the cause of the problem. Then refer to the fact sheet for management options specific to that host plant and causal organism.