Rose rosette virus is a rapidly emerging problem on roses in the Midwest. It has been a serious problem on multiflora (wild) roses in pastures, woods and field edges. In past years a rapid emergence has been observed on domestic roses. It is often referred to as witch's broom, a disease that causes plant growth resembling a witch's broom. Early symptoms of this disease are rapid stem elongation, followed by certain branches of the plant developing thickened, abnormally thorny stems. Then, many short, deformed shoots will form, often displaying a red pigmentation and smaller, misshapen leaves. Usually plants die within a year or two as the disease spreads throughout the plant. The disease is moved from infected plants to healthy ones by insects and mites. Herbicide exposure can be mistaken as rose rosette, but the rose usually outgrows the effect of herbicide and the new growth is healthy. Roses affected by rose rosette disease never recover. At this time, there is no effective control for this disease. Infected plants should be removed and destroyed.
MU Extension publication G6600, Roses: Selecting and Planting
MU Extension publicaiton G6601, Roses: Care After Planting