How to Get Rid of Powdery Mildew on Pentas

Look for small, white spots on the pentas' leaves. These will quickly grow together and eventually cover the leaves with a fine, white layer of mildew, making the plant look "dusty."

Rub off the fungus if the infection is mild. Use a dry cloth and simply rub the leaves clean. Do not wash the fungus off with a hose, however, as wet leaves can give rise to the fungus. In fact, never water your pentas from above, as this wets the blooms and foliage, which increases the chance of the plant developing powdery mildew and other fungal diseases.

Prune off any heavily infected leaves or branches if the fungus is limited to one area of the plant. Dispose of the infected foliage in a trash bag. Make sure no infected leaves are left lying on the ground near your pentas, as the fungus can overwinter in the soil.

Spray your pentas with a sulfar-based fungicide formulated to get rid of and prevent mildew. Follow the directions on the bottle. For best results, begin treating your pentas as soon as you see the first symptoms of powdery mildew, and repeat the application of the fungicide throughout the growing season as directed by the instructions on the fungicide.