Lettuce is hardy and can be planted as early as the soil can be worked. It's mostly a coolw eather crop and grows best in temperatures of 60-65 degrees.
Sweet, tangy red and green leaves that are great in salads and on sandwiches. When harvesting, cut the outer leaves first and harvest in the morning hours. You can grow lettuce in gardens, containers, or raised gardens. 
 
Height (mature): 5-10 inches
Sun: Partial sun