Is a White Fuzzy Growth Covering an Azalea Bloom Normal?

Powdery Mildew

• Powdery mildew causes a fuzzy, powdery white or grayish growth on plant matter. It is more common on leaves, though it can also travel to flowers and buds. New growth is stunted and infected leaves and flowers may drop prematurely. If the infection is heavy, you can combat it by spraying it with a horticultural oil such as neem or jojoba oil. Cover the plant evenly. Do not apply when temperatures are above 90 degrees Fahrenheit or if the plant is water-stressed.

Petal Blight

• Petal blight exclusively attacks flowers, initially appearing as small white growths on the petals. Over time, spots turn brown and watery, increasing in size. Eventually the flowers rot and turn brown. According to the Clemson Cooperative Extension, the best defense against petal blight is to pick and destroy all infected flowers and avoid overhead irrigation, as wet conditions breed fungus. Remove dropped flowers and replace any existing mulch with fresh, sterile mulch, as the fungus can overwinter in plant matter.

Leaf and Flower Gall

• Leaf and flower gall affects both flowers and young leaves, causing swollen galls that turn white as spores form on the surface. Galls eventually harden and turn brown. Remove any plant matter with galls on it and destroy it. If the disease continues from year to year, you can apply a fungicide containing mancozeb on new flowers and leaves. Once leaves are mature, stop applying the fungicide. Follow the rates and instructions listed on the label.

Prevention

• Healthy, happy azaleas are less likely to develop disease. Azaleas range in hardiness, with most growing in U.S. Department of Agriculture plant hardiness zones 4 to 9. According to Floridata, azaleas require an acidic, consistently moist soil generously enhanced with organic matter and mulched with leaves or pine needles. Some varieties prefer full sunlight and some prefer full shade, though most thrive in partial shade. Water regularly, ideally in the morning, and avoid splashing the leaves.