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.
This lettuce plant is known for its 'buttery' taste and velvety texture. It forms a small loosely formed head, are is slightly more tolerant of heat than other lettuce plants. Partial shade, or a location that receives primarily eastward exposure may be helpful if you're going to be growing this lettuce in the summer.