|'Eclipse', also known as 'Salamander', 'Black-Seeded Tennisball', 'Sutton's Matchless', and 'Tender and True', is an heirloom variety which was one of the most popular lettuces of the 19th century. This is a dark green lettuce which is often forced rather than grown in the field. If the weather is unusually warm, the leaves tend toward bitterness. Start from see 4 to 6 weeks before average last frost date. Sow seeds 1/4 inch deep in wide rows and thin to 8 to 12 inches apart. Thinned seedlings can be replanted. Keep soil moist but not soggy. Protect from rabbits and slugs. Extend the harvest season by planting successive crops. Summer heat causes lettuce to bolt. Pick outer leaves as they grow or harvest all at once. Harvesting when weather or day temperature is cooler will result in crisper leaves. Do not harvest lettuces until you are ready to use it.