Peggy Sellers, Master Gardener State Coordinator
Oak leaf blister is caused by the fungus, Taphrina caerulescens. All oak species are susceptible. Symptoms on oak leaves appear as initially as pale green to slightly yellow circular bulges or "blisters" on upper leaf surfaces. The blisters may be 1/8 to 1/2 inch in diameter. The blisters appear as depressions when the lower leaf surface is observed. Eventually the blisters may appear as a bright yellow-green color, and as the season progresses the blisters turn brown. Although heavy infection can result in defoliation, significant leaf drop on oaks in the Midwest is usually not observed. Chemical control is usually not warranted. Collect and destroy fallen leaves.
 |
 |
| Oak Leaf Blister-Early and Advanced Sysmptoms | Oak Leaf Blister |
|---|---|
 |
 |
| Oak Leaf Blister (Top) | Oak Leaf Blister (Underside) |
|Top |
Plant and Pest Digital Library and Digitally Assisted Diagnosis, Purdue University, West Lafayette, Indiana.