Start seed indoors 3-4 weeks before transplanting into the garden. Optimum soil temperature for seed germination is 65-85 degrees. Transplant to the garden 2 to 3 weeks after your average last frost. Or, plant seeds directly in the garden 1-2 weeks after average last frost date. Sow 3-5 seeds per hill, thinning to a final 2-3 plants per hill. Pumpkins grow best in a warm site with full sun. Warm soil is essential to good seed germination and emergence. Using transplants can speed production.