Apply all chemicals according to directions on the label. This fungal disease, caused by Ovulinia azaleae, primarily affects the flowers of azalea, but mountain laurel and rhododendron flowers can also be infected. Indian and kurume azaleas are especially susceptible. On colored flowers the spots are white, and on white flowers the spots are brown. The spots quickly enlarge and become soft and watery.
Flowers rot and stick to the leaves.
Infection is easily spread from flower to flower by wind, rain and insects. The fungus survives the winter in the soil. This fungus survives in the soil, so it is important to replace the ground litter with uncontaminated mulches. Fungicides are available for cases of severe infection on azaleas. Select a product that contains captan, chlorothalonil, maneb, PCNB, triforine, vinclozolin or triadimefon.