Heat tolerant green summer crisp with open heads. The leaves have characteristics of both a romaine and a greenleaf, and are arranged in a whorl, giving the plant a unique vase-like shape. Leaves are thick, juicy, and flavorful. Packet: 30 seeds. Days to Maturity or Bloom: 51 CULTURE: Lettuce is hardy and can be planted as early as the soil can be worked. It is a cool weather crop and makes its best growth at temperatures of 60-65°F (16-18°C). Careful variety selection is important for hot weather crops. Sow every 3 weeks for a continuous supply of fresh lettuce.