Question From: D. Kamp - Prospect Heights, Illinois, United States
Q: My impatiens recently dropped leaves, a nearby lilac has a powder on its leaves, and my vegetable garden is 200 feet from these but the zucchini has powder on leaves and the cucumbers have wilted away. The vegetables are watered via drip irrigation at base of plant, impatiens from sprinkler heads. All are a loss but how can I prevent this from happening next year?
The diseases that struck your plants are in the powdery mildew family. The impatience may have downy mildew. Check the backs of the leaves to see if there is a gray coverig. I would not plant impatiens in space for a couple of years as the fungal spores can live in the soil. New Guinea Impatiens or begonias are options. Spraying your cukes and zucchini with a fungicide making sure to cover the undersides of the leaves will prevent most fungal diseases. Best And Happy Yardening, Nancy