Poplar trees

The fungus that causes this disease is common throughout the west. Most native and hybrid poplars are susceptible, including the Aspen, Balsam poplar, Brooks hybrids and others. It is first seen as small knobby, bumpy growths on twigs and small branches. Infections on larger branches and trunks display rough bark and swollen areas with dark black fissures in the bark. The fungus can attack any size of branch or trunk. Watering to increase Tree vigor and pruning to reduce the population are the remedies.