Buttercrunch Lettuce Seed. Heirloom Buttercrunch Lettuce is a butterhead type lettuce that forms a loose head 4" - 5" across. The center of Buttercrunch Lettuce blanches to a yellow - white color. Buttercrunch Lettuce withstands heat. Buttercrunch Lettuce is not as quick to bolt as some others. Harvest Buttercrunch Lettuce when desired size is reached. Buttercrunch Lettuce is fully mature at 65 days. Packet contains approximately 250 seeds grown naturally with love and care. Happy Planting! We have a wide variety of Heirloom Vegetable, Herb, and Flower Seeds for sale. With all of our seeds: Your first packet ships for $2.50. All additional packets ship free. So your total shipping on a seed order is $2.50 no matter how many packets you order.