Powdery mildew is a general name for a few different species of fungi that infect several ornamental plants, such as zinnias,Monarda, lilacs, and roses. It also affects vegetables and fruits, including beans, grapes, cucumbers, beets, melons, and squash to name a few. It can affect the flavor and reduce yields of some fruits and vegetables. Prevention and control is important. Powdery mildew is found throughout North America. It appears as a gray talcum-like powder on leaves and may spread to... Read more