Looseleaf lettuce is the faster growing type and can be grown anywhere as long as you have composted soil. Lettuce grows best if planted indoors and transplanted outdoors in early spring. Lettuce does well in composted soil. It does not do well in clay soil. Plant your seeds indoors 3 to 6 weeks before setting outside. Lettuce will better tolerate heat if plants are well thinned and air can circulate around them. Spring planting should occur as soon as soil can be worked, and fall planting done around June or July. Plants grow 2 - 10" tall.