Oak Leaf Blister: Harmless Fungal Spots on White Oak

Diagnosis Confirmed

The circular, blister-like, pale green spots on your white oak leaves—without winding trails—are classic oak leaf blister (Taphrina caerulescens), a common fungal disease. It is cosmetic and does not threaten tree health.

No Treatment Needed

• Do not prune infected branches; the disease does not warrant canopy removal.
• Do not spray fungicide; it's ineffective and unnecessary.
• Rake and destroy fallen leaves in autumn to reduce inoculum for next year.

Key Points

The fungus is airborne and present every year; severity varies with spring weather. Your tree will continue to thrive. No action caused this—it's a natural occurrence.