Leaf Blisters and Curls
Fungal diseases that cause distorted, curled leaves on many trees. Oak leaf blister can defoliate and even kill oak trees. Blisters are yellow bumps on the upper surface of the leaves, with gray depressions on the lower surface. This disease can defoliate and even kill oak trees. Peach leaf curl attacks peaches and almonds. New leaves are pale or reddish. The leaf’s midrib doesn’t grow, causing the leaves to become puckered and curled. Fruit is often damaged and bad cases can kill the tree. Both diseases are controlled with a single horticultural spray just before buds begin to swell in late winter and again in autumn when the leaves start to fall.