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Phomopsis twig blight, which is caused by the fungus Phomopsis juniperovora, is a common and damaging disease of arborvitae, cypress, juniper, red cedar and related evergreens. Varieties of juniper most susceptible to Phomopsis blight include J. sabina var. tamarisfolia, "Nicks Compact Pfitzer", "Andorra", "Bar Harbor" and "Blue Rug." Frequent shearing and heavy fertilization with nitrogen may increase the severity of Phomopsis blight.