•Direct Sowing: Sow lettuce seeds directly into the garden as soon as the soil can be worked, as seeds germinate at temperatures of 40°F (4.4°C) and above.
•Transplanting: You can also start lettuce seedlings indoors and transplant them into the garden after the threat of frost has passed.
•Seed Depth: Sow seeds 1/4 to 1/2 inch deep.