Learn how to identify, prevent, and treat powdery mildew with this guide. Discover organic and chemical treatment options, as well as management strategies for long-term control.

St. Paul, MN (May 2019)--Phasey bean, also known as wild bush bean, is an invasive species native to the tropical Americas and the Caribbean. In 2017, the Florida Exotic Pest Plant Council (FLEPPC) ...

“Help, my plant is covered in a white, powdery fungus! What do I do?” First, don’t panic. While powdery mildew may not look pretty, it rarely causes significant damage except in cases of severe ...

Powdery mildew is a fungal disease affecting many plants, causing a white or gray coating on leaves and slowing growth. The fungus thrives in warm, dry weather with high humidity, especially in ...

One of the most important factors for lima bean growers in Delaware and throughout the world is the ability to accurately measure and forecast disease occurrence in their fields during the growing ...

Powdery mildew – or PM – can be a farmer’s worst nightmare. The mildew is easy to spot as it appears on the leaf as a matte-white frost—almost like that fake snow spray you often see around Christmas ...

October 2025 | Written by: Andrew Kness, M.Sc. Extension Research Assistant, Nathan Kleczewski, Ph.D. Extension Plant Pathologist, Kathryne Everts, Ph.D. Extension Vegetable Plant Pathologist Downy ...

“The leaves of my peonies are covered with what appears to be a white mold, with some of the leaves even turning brown already. What is this problem, and will it affect the plants next year? Should I ...

The grayish white powdery growth you are seeing on the dahlia leaves is caused by a fungus and can also be a common garden problem on other plants. Many species of fungi can cause powdery mildew on ...

Steve Nix is a member of the Society of American Foresters and a former forest resources analyst for the state of Alabama. Powdery mildew is a disease common in trees that appears as a white powdery ...

Q: Ive got a Diabolo ninebark thats been getting a whitish powder all over the leaves. Eventually the leaves drop. Its looking pretty bad. What should I do? A: The problem is powdery mildew, a fungal ...

Wide range, but particularly common to cucurbits (zucchini, pumpkin, cucumbers etc), strawberries, peas, roses, dahlias, grapes, hydrangeas, mangoes and tomatoes. Powdery mildew can often be the ...