- Name: Prairie Phlox - Other Common Names: Downy Phlox - Scientific Name: Phlox Pilosa - Color: Mixed Colors - White, Light Pink, Dark Pink, Light Purple, & Dark Purple - Plant Seeds: Outdoors After Frost / Fall / Cold Stratify / Indoors Weeks Before Last Frost - Plant Height: 12 - 18" - Plant Spacing: 12" - Bloom Time: May – July - Hardiness Zone: 3 – 9 - Light Requirements: Sun - Part Shade - Soil & Water Preferences: Average – Dry - Quantity: 20 Seeds