Cool season crop. In early spring, direct-sow seeds 1″ apart in fertile, well-drained soil. Or sow indoors 4 weeks before last expected frost. Lettuce needs 4 weeks before last expected frost. Lettuce needs light to germinate, so barely cover and keep evenly moist. thin to recommended spacing when seedlings are large enough to handle. Harvest entire head when they are sized up and firm. Sow again in late summer for a second crop.