Why does your Rhododendron prunifolium have white powder? Diagnose the cause and fix it with our step-by-step guide.
This fungal disease is common in Rhododendrons when humidity is high and air circulation is poor. It manifests as a white, flour-like coating on the surface of the leaves, which can eventually lead to leaf yellowing and premature drop.
Mealybugs are small, soft-bodied insects that secrete a white, waxy, cottony substance to protect themselves. They cluster in the crevices of the plum-leaf azalea stems and under the leaves, feeding on plant sap.
If the plant is frequently overhead watered, calcium or magnesium carbonates from hard water can leave white, crusty deposits on the foliage. Unlike fungi, these deposits are usually more rigid and localized to where water droplets dried.
Your plant might also be experiencing one of these issues:
English
Italiano
