USDA Zone: 9-12(Dahlia grow still in 7 and 8 zone,but end in winter if no greenhouse,you have to replant them in next year) Category: Annual, Bloom Time: Summer to autumn, Height Range: 8-24 Inches, Space Range: 9-12 inches, Lowest Temperature: 20° to 30°F, Environment: Full Sun to Part Shade, Companion Plants: Alyssum, Salvia, Marigold, Seed Planting note, Put seed in water for 24-48 hours before planting them is necessary,Germ Temperature: 70-85F, Average Germ Time: 7-14 days,Light Required: Yes,Depth: Lightly cover with top soil,Moisture: Keep seeds moist until germination