Plant seeds directly in the garden after average last frost date when soil has warmed up. Optimum soil temperature for seed germination is 65-75°F. Or, start seed indoors 4-6 weeks before your anticipated planting date. Set transplants in the garden after danger of frost has passed. Do not disturb roots when transplanting. Remove spent flower buds promptly to encourage new growth. Dahlias will produce tubers that can saved and planted out the following spring. In autumn, after plants have died back but before ground freezes over, cut them back by 2-4" above soil and carefully remove tubers. Remove excess soil, cure tubers for a few days and pack with vermiculite.