The disease usually appears in midsummer. It is most damaging in cool, rainy weather. Early in spring, infected shoots turn gray-brown. Mature stems rot at ground level. A mass of gray-brown feltlike spores appear on leaves and stems.
Young buds dry up, and shoots and mature buds and flowers soften and rot.
Infected petals drop onto healthy leaves and spread the disease. QRemove diseased parts as soon as you notice them. Pull out and burn badly infected plants. Cut plants to the ground after the foliage turns brown in the fall. Burn dead material.