Crapemyrtle – White Substance On Leaves
Q: I have a crape myrtle with a white substance on the leaves and no blooms. What do I have? How do I treat it?
A: I’m almost certain you have powdery mildew. Cool nights and warm, humid days provide the perfect environment for this disease to develop. Heavy winter pruning causes lush growth with little air circulation around the leaves. Myclobutanil (Immunox) and propiconazole (Infuse) will control the disease on new leaves.