- A Butterhead variety that is very productive and quick to mature as it matures to the size of a baseball.
Tom Thumb Butterhead Lettuce Seeds. 55-60 Days. Heirloom, Non-GMO. Lactuca sativa. Highly productive, dwarfed bibb lettuce that is quick to mature no bigger than a baseball or tennis ball, the Tom Thumb lettuce is an early 19th century American heirloom still popularly grown for quick, steady harvests.