white leaves on zucchini plants

Asked July 9, 2019, 10:42 AM EDT

Every year my zucchini plants get a dry white powdery substance on leaves and the flowers fall off without producing any zucchini. I have put them in different boxes with different dirt and still it happens. Some of my neighbors also say the same has happened to their squash plants. Is something in the air, is this a spore? What can be done?

Thurston County Washington vegetable gardening

1 Response

Thank you for your question. Although it helps to have a photo of the problem, it seems certain that what you are describing is one or more of a group of fungi causing powdery mildew. Here is a handbook page on the problem and its control: https://pnwhandbooks.org/plantdisease/pathogen-articles/common/fungi/powdery-mildew-diseases Hope this is helpful.