Combatting Powdery Mildew: Prevention & Treatment Guide

🍄 Combatting Powdery Mildew: Prevention & Treatment Guide

Powdery mildew—that white, flour-like dusting on your plants—isn’t just unsightly. It weakens leaves, hinders flowering, and, if ignored, spreads quickly through your garden. But with the right approach, you can keep this common Illinois garden problem under control.

🌱 What Does Powdery Mildew Look Like?

White or gray powdery spots on leaves, stems, or fruit

Typically begins on lower or shaded foliage

Leaves may yellow, curl, dry out, or fall off prematurely

🌤️ How to Prevent It

Powdery mildew thrives in shady, humid conditions. Your best defense? A garden with great air circulation and early action.

✅ Increase Airflow & Light

Prune overgrown areas

Space plants properly

Avoid crowding tall perennials like phlox and bee balm

✅ Water Early, Not Late

Always water at the base in the morning

Avoid wetting foliage in the evening

✅ Choose Resistant Varieties

Look for mildew-resistant versions of:

Cucumbers and squash

Grapes and zinnias

Roses and lilacs

✅ Clean Up Debris

Remove fallen leaves and any infected material—especially at the end of the season—to reduce overwintering spores.