Azalea Leaf Gall: Fungal Disease Identification and Control

Recognizing the Distinctive Galls

Azalea leaves swelling into thick, cream-colored, then brown, succulent distortions indicate azalea leaf gall (Exobasidium vaccinii)—a fungal disease transforming leaf tissue into spore-producing galls. It's cosmetic, not lethal.

Control Options

Cultural (preferred): Hand-pick and trash galls before they turn white (spore stage). Reduces inoculum for next year.

Chemical (preventive only): Fungicide at bud break next spring (chlorothalonil, mancozeb, or copper). Once galls form, sprays don't help current season.

Key Points

• Does not kill the plant.
• Annual occurrence in humid springs.
• Remove galls before they sporulate (white powdery stage).
• Improve air circulation; avoid overhead watering.

This is a manageable aesthetic issue, not a health crisis.