Direct sowing
In late summer, at least 12 weeks before the ground freezes, sow seeds in groups of 3–4, 1/8 in deep. Cover with 1/4 in of fine soil, firm lightly, and keep moist. Seedlings should appear in 10–20 days. 
Starting indoors
Sow seeds in a sterilized seed starting mix in a small pot or seed cell tray. Cover with ¼ in of loose seed starting mix. Keep the soil moist and at a constant temperature of 65–70°F (18–21°C) until seedlings emerge. Provide bright light for up to 16 hours a day and at least 8 hours of darkness. Once seedlings have two sets of true leaves, transplant them to a larger container.