Azalea Diseases Explained

Azaleas are beautiful flowers that are easy to plant and maintain, and they bloom in many different colors. Read on to learn about the causes, effects and treatments of a few diseases that affect azaleas.

Root Rot

Root rot is a serious, but common disease that is caused by excessive moisture in the soil. This disease occurs in poorly-drained and clay-heavy soils.

Prevent root rot by planting azaleas in soil with good drainage. You must also avoid over-watering or placing the plant too deep in the soil. Never plant new azaleas in spots where root rot has occurred.

Leaf and Flower Gall

This is a fungal infection that is mostly seen in moist growing conditions. This infection causes abnormal growths called galls that appear on the leaves and flowers. During the initial stages, the growths are green and soft. As the infection progresses, the galls become white in color and spread to other plants.

Control leaf and flower gall by plucking out the fungal growths before they turn white.

Petal Blight

Petal Blight is a disease caused by the Ovulinia Azalea fungus. Petals first exhibit small slimy spots that increase in size and gradually cause petals to droop.

This disease can be controlled by spraying fungicide in the initial blooming stage and reapplying at regular intervals. Quarantine the infected plants for best results.

Powdery Mildew

Powdery mildew is caused by the fungus Erysiphe azaleae. As the name suggests, the disease looks like a powdery white growth on both sides of the leaves. It is more prevalent in shaded and humid conditions.

Control powdery mildew by plucking out and destroying the infected leaves, and spray it with an appropriate fungicide.