Leaf Gall (Blisters)

Madrone foliage occasionally develops blister-like galls, typically minor and localized. Gall-causing organisms usually cause only cosmetic damage. No management is required unless galls are numerous and severely disfiguring. Most affected trees remain vigorous.

Galls are abnormal growths triggered by the pathogen and cannot be reversed once formed. Prune out galled tissue when practical, cutting well below the affected area. Avoid wounding plants during maintenance, as many gall-forming organisms enter through fresh injuries. For severe or recurring gall problems, consider whether the species is well-suited to the site conditions, as stressed plants tend to be more susceptible.