|'Brown Cos' is an heirloom variety with cool grey-green leaves tinged with red on fringes, veins, and stems. Well-grown heads measure 14 inches in diameter. In Southern states this variety can overwinter, but it is generally planted in the late summer, and is ready for harvest in the fall. Start from seed 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.