Search Articles

Powdery Mildew

Powdery mildew

Powdery mildew. Photo: Ann Whitman

A powdery white growth on leaves is the first evidence of this fungal disease, which affects beans, cucumbers, squash, pumpkins, lettuce, peas and many other kinds of plants. The fungus can spread to flowers and fruit. New growth and succulent plant tissues are particularly vulnerable to infection. Infected areas eventually turn yellow and dry up; severe infection can weaken or even kill entire plants.

Unlike other fungal diseases, powdery mildew does not require wet foliage for infection to occur, although it does require high humidity. It can spread quickly in warm, dry climates. The fungus overwinters on plant debris.

Prevention and Control

  • Plant powdery mildew-resistant varieties, such as Super Sugar Snap pea.
  • Water plants as needed to prevent moisture stress.
  • Keep plants well spaced and weeded to optimize air flow around the leaves.
  • Avoid excess nitrogen fertilizer, especially late in the growing season.

Share This Article

Related Products

$14.95 - $29.95
$7.95 - $12.95
$19.95
2 or more $19.00 each

Sign Up for E-mail

Get the latest news, tips and gardening info!

Sign Up
Looking for Product Instructions?

Assembly instructions, diagrams and other types of product information are available on product pages. To find it, search for the product, go to the product page and click on the "How-To and Instructions" tab.

We're a B Corp!

Gardener's Supply is pleased to be part of a class of companies called B Corps. With this certification comes a dual mission that combines bottom-line success and social responsibility. In short: Do well and do good.

Learn More

Learn and Share

Our website is packed with how-tos and inspiration, as well as opportunities to share with fellow gardeners. Check back often to view new articles, videos, blog posts and Facebook updates and join our online community.

Learn & Share

Satisfaction Guaranteed

We stand by the quality of our products and our service. If for any reason you're not satisfied with your purchase, you can return it to us for an exchange, refund, or credit.

Learn More