Azaleas are perennial shrubs grown for their spring flowers and lush foliage. When azaleas lose their leaves, it may be normal leaf drop, or it may be due to water or disease problems.
Azaleas are deciduous or evergreen. Deciduous azaleas drop or lose all their leaves in the fall. They may lose leaves earlier in the season due to dry weather. Evergreen azaleas have two sets of leaves. They lose one set of leaves in fall and keep the other set as winter foliage.
Azaleas often lose leaves due to too little or too much water. When plant roots dry out, the leaves drop off. Prompt watering may revive these azaleas and encourage foliage the following season. Too much water causes roots to rot. Over-watered azaleas lose their leaves and die from waterlogged roots.
Azaleas lose leaves when they are infected with disease. Humid weather and overhead watering encourage leaf spot and other fungus problems. Leaves develop fungus blotches and curl or fall off the plant. Fungicides applied promptly usually control serious damage.