The Best Phlox Varieties for Mildew Resistance and Long Bloom

Why Phlox?

Summer phlox is widely adapted (Minneapolis to Gulf Coast) but plagued by powdery mildew. We consulted experts and gardeners nationwide to find the most resistant, long-blooming, healthy varieties. Phlox lifts the summer garden with jewel-box colors and perfume—among the most gratifying perennials.

Even resistant varieties aren't mildew-proof. Keep phlox healthy:

• Full sun, rich, porous soil; plant spring or fall.
• Feed regularly: compost at planting, balanced fertilizer annually.
• Mulch to keep soil cool and moist; avoid wetting foliage.
• Divide every 3–4 years; thin to 8 stems max in spring.
• Cut stems to ground after frost; discard (don't compost) to remove overwintering spores.
• If mildew appears, treat with horticultural oil spray.

Top Phlox Picks

'Natascha' – Pink-and-white pinwheels from June to fall.

'Miss Lingard' – Slender, crisp white flower heads.

'Katherine' – Soft color radiating from large floret centers.

'Laura' – Longest-blooming phlox in our Test Garden.