You might be noticing powdery mildew (a disease that causes a grayish, powdery film on leaves) in your garden. Common plants that could be affected are lilacs, phlox, bee balm, zinnias and nannyberry ...

“My red rhododendron looks as if it has a layer of ash or white powder on it (above). What should I do?” asks Birds & Blooms reader Steven Graves of Aptos, California. Horticultural expert Melinda ...

Powdery mildew is a fungal disease affecting many plants, causing a white or gray coating on leaves and slowing growth. The fungus thrives in warm, dry weather with high humidity, especially in ...