Taphrina pruni being larger than the healthy one. As a fungus, cool and wet weather conditions promote the germination of spores, whilst warm and dry weather results in infection rarely taking place. Colonisation can become extensive and eradication very difficult. The disease can to some degree be controlled by carefully removing infected branches, witch's brooms and fruit before the infective air borne spores are produced. Applications of copper-containing fungicides have a degree of control over the fungus. Taphrina pruni Taphrina pruni is a fungal plant pathogen of blackthorn (Prunus spinosa) that causes the Pocket or bladder Plum gall, a chemically induced distortion
Prunus serrula typical of "Prunus", are produced in clusters of one to three. The fruit is a small oval bright red drupe. "Prunus serrula" is grown as a ornamental tree, especially for winter interest. It tolerates a variety of soil types and has a wide pH range. It prefers full sun and does well in USDA hardiness zones 5 to 8. Its potential as an invasive species is low, as it is susceptible to many common garden diseases and pests such as fire blight, powdery mildew and Japanese beetles. It is sometimes grafted to "Prunus serrulata" (Japanese cherry) crowns, forming a tree