WSU Extension

Hortsense

Common Diseases : Galls
(revision date: 4/30/2013)


Use Integrated Pest Management (IPM) for successful plant problem management.

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

Non-Chemical Management
  • Remove and destroy galls if the causal organism can spread to other susceptible plants.
Select non-chemical management options as your first choice!

Chemical Management
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides

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

Images
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Caption: Camellia leaf gall
Photo by: R.S. Byther
Caption: Dahlia crown gall
Photo by: R.S. Byther
Caption: Dahlia root knot
Photo by: R.S. Byther
Caption: Madrone leaf gall (blisters) on leaves
Photo by: R.S. Byther
Caption: Azalea leaf and flower gall
Photo by: R.S. Byther
Caption: Azalea leaf and flower gall
Photo by: R.S. Byther
Caption: Crown gall on roots
Photo by: R.S. Byther
Caption: Raspberry crown gall
Photo by: R.S. Byther
Caption: Mossy rose gall
Photo by: R.S. Byther
Caption: Rose spiny leaf gall
Photo by: R.S. Byther
Caption: Peach leaf curl distorted growth
Photo by: R.S. Byther
Caption: White powdery coating of peach leaf curl fungus
Photo by: R.S. Byther
Caption: Douglas-fir bacterial gall
Photo by: R.S. Byther
Caption: Douglas fir mycorrhizae
Photo by: R.S. Byther
Caption: Crown gall
Photo by: R.S. Byther
Caption: Blackberry crown galls
Photo by: R.S. Byther
Caption: Jumping oak galls
Photo by: A.L. Antonelli
Caption: California gallfly "oak apples"
Photo by: R.S. Byther