How to Control Powdery Mildew in the Garden

White or gray dust on leaves signals powdery mildew, a common fungal disease with many host-specific strains. There's no cure once established, but you can control it.

Control Strategies

Sanitation: Remove and trash all infected fallen leaves during and after the season. Pluck newly infected leaves immediately.

Air circulation: Space plants adequately. Divide perennials, prune shrubs, and avoid planting mildew-prone varieties in sheltered spots.

Fungicides: Apply preventively in humid conditions or at first sign. Both traditional and organic products work. Find them at garden centers.

Choose Resistant Varieties

Many plants have been bred for resistance. Top performers include: 'Adirondack' crabapple, 'Aurora' dogwood, 'Blue Stocking' bee balm, 'Bonica' rose, 'Cherokee Brave' dogwood, 'David' phlox, 'Donald Wyman' crabapple, 'Hopi' crape myrtle, 'Iceberg' rose, 'James McFarlane' lilac, 'Marshall's Delight' bee balm, 'Miss Kim' lilac, 'Natascha' phlox, 'Natchez' crape myrtle, 'Olympiad' rose, 'Prairifire' crabapple, 'Profusion' zinnias, 'Sexy Rexy' rose, 'Sheer Bliss' rose, 'Topaz Jewel' rose, 'Violet Queen' bee balm, 'Zahara' zinnias.