Downy Mildew

Don’t confuse powdery mildew with downy mildew!

Downy mildew is more closely related to algae, producing grayish fuzzy-looking spores on the undersides of leaves.

Look for pale green or yellow patches on the upper surfaces of older leaves to diagnose downy mildew. The fungus will have a white to grayish downy substance on the lower surfaces, similar to cotton.

Downy mildew thrives in cool, humid environments, such as early spring or late fall.

Downy mildew can be controlled by keeping moisture away from leaves or using proper fungicides. It is important to carefully select a fungicide, as some are ineffective against downy mildew. Earth’s Ally’s fungicide will control both powdery and downy mildew.