Q. Can you suggest the best way to treat powdery mildew on pumpkins?
Late summer is prime powdery mildew season. Probably one of the simplest and easiest answers is to use horticulture oil or horticulture soap. You should be able to get it at a good garden center. Be sure to use a low concentration of one percent. It will say one percent on the container.
When using chemicals, always make sure the product is labeled for whatever you want to treat. So the label should say it treats powdery mildew. Always follow the application directions.
You can also try potassium bicarbonate (not sodium bicarbonate, which is baking soda, but potassium bicarbonate). Milstop® and Armacarb® are two brand names; potassium bicarbonate is the generic ingredient.
For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service