I received a frantic call from one of our growers last week. She walked down to the garden after being out of town a few days and came back to a flour or “powder” like substance on her plants. “What do I do?” she asked. She was afraid all of her hard work had been for nothing. She feared that it was only a matter of time before her garden was a goner.

What is it?

Powdery mildew. Powdery mildew is a fungus that spreads easily in late summer with warm days and cool nights. You can find it on beans, melons, squash and other vegetables. Although it is unsightly and can cause some reduction in yields and affect flavor of the plant, it normally doesn’t kill the plant.

What to do?

In the case mentioned here, we caught it pretty early. We carefully removed affected leaves and disposed of them in a sealed trash bag to be safe. We made sure to pull any weeds to make sure the plants received plenty of air circulation and sunlight. The grower will be using an organic fungicidal spray to slow the growth. With proper care, the plants should continue to produce with little effect from the unsightly powdery mildew.