Oak Leaf Blister/Curl

Oak leaf blister/ curl Common name Oak leaf blister/ curl Causal agent Oak leaf blister is a fungal disease caused by a pathogen of the genus Taphrina. Although it affects almost all species of oak, red oak is more prone to be attacked. Scientific name Taphrina caerulescens Symptoms & Signs The initial symptoms include raises and brown blisters on the upper surface of the leaves. On the underside of the leaves, there is a slight depression at the site of the blisters. Due to many blisters, the leaf curls and falls prematurely, causing premature defoliation. Transmission The fungal spores travel to other healthy plants through wind and water that infects the plants. Cool, wet weather favors the growth and spread of infection. Time of concern Early spring to late summer Common hosts Red oak English oak Sessile oak Quercus ilex