Powdery Mildew is one of the most common and recognizable plant diseases. It affects almost all plants but some are more susceptible than others.
Here in New Mexico, powdery mildew is common on roses, euonymus, crape myrtle, lilacs, verbena, sunflowers, photinia, zinnia, turfgrass and many other ornamentals plants, fruits and vegetables.
It appears as grey or white powdered splotches on the leaves and stems of plants, and even though this fungi may not be visible on top of the leaves, it can be affecting the lower leaf surface, stems, flowers, buds and even the fruit. Be sure to inspect the plant carefully on both top and bottom on the leaves.