Introduced in 1888 by W. Atlee Burpee under the name California Cream Butter. This large, cabbage-like salad lettuce was quickly reselected and improved by Philadelphia seedsman William Henry Maule so that by the 1890s it became commonly known as Maule’s Philadelphia Butter. Long considered the “mainstay of the Philadelphia market,” this lettuce was treated as a fall forcing lettuce and as such is ideal for cold frame and polytunnel culture. For best appearance, plant 14 inches apart. This lettuce thrives in cool weather and can be overwintered under straw.