Powdery mildew is easily identified by the presence of white to gray mycelium on affected leaves and/or flowers. The first sign of disease is usually isolated colonies of white fungal growth. With time, whole leaves may be completely covered with fungal growth.

On some plants, such as pin oak, mildew may be present only on the undersides of leaves. On dogwood, crape myrtle, and nandina, infected leaves may be curled, twisted, or otherwise distorted. Leaves may be abnormally red with little mycelium visible. On sedum, lesions are scabby and brown.

Use disease resistant cultivars for crabapple, crape myrtle, dogwood, lilac, rose, and zinnia.

For chemical control recommendations, consult the Insect and Plant Disease Control Manual, UT Extension Publication 1690, found here. Please contact your local Extension office for specific pesticide recommendations.