How to Grow Butter Lettuce

A cool weather lettuce variety, butter lettuce (Lactuca sativa var. capitata), also called butterhead lettuce, grows best in the spring and fall. This variety forms heads 7 inches in diameter or more, made up of loose outer leaves and a semi-compact center. Butter lettuce is ready to harvest 60 days after planting when it forms a full, loosely assembled head.

Grow butter lettuce in full sun or part shade. As a general guide, part shade refers to a spot that gets between two and four hours of sun per day, and full sun means six or more hours daily.

Mix compost or fertilizer -- pick one -- with the soil before planting. Use a 2- to 4-inch-deep layer of seasoned compost or 1/2 cup of 10-10-10 fertilizer. One-half cups of fertilizer is enough for a 10-foot row. Dig the soil amendment 6 inches deep in the soil before planting butter lettuce.

Plant butter lettuce early in the spring, as soon as you can work the soil. Lettuce seeds germinate in soil cool at 35 degrees Fahrenheit. If you are planting butter lettuce from starts, wait until the last frost date before planting out. Butter lettuce grows best in cool spring and fall weather. In summer, this variety, in particular, tends to bolt and get bitter.

Space the seeds 1 inch apart. As the seedlings grow, thin them to a spacing of between 4 and 10 inches. Wait until the seedlings average about 1 inch tall before thinning. To thin, pull out extra seedlings, keeping the strongest and most vigorous plants. Plant starts 4 to 10 inches apart.

Butter lettuce needs regular, consistent watering. Keep the soil damp through the growing season by watering when the top of the soil feels dry. Keep an eye on the leaves, and water if you notice any sign of wilting. Water thoroughly until the water is damp 3 to 4 inches deep. On sunny days, water early in the morning or in the evening. Water droplets on the leaves can magnify sunlight and cause burning.

Butter lettuce needs between 1 and 2 inches of water a week.

Fertilize one month after you thin the seedlings. If you planted starts, apply fertilizer a month after planting out. Use a nitrogen-heavy fertilizer such as a 21-0-0 mix to encourage lots of leafy, green growth. For a 10-foot-long row, sprinkle a total of 1/4 cups evenly over the soil.

After fertilizing, water right away to help break down the fertilizer and moisten the soil around the roots.

Pull weeds by hand or use a hoe lightly on the surface of the soil to gently dislodge weeds.

Mulching, while not crucial for growing butter lettuce, does help keep weeds down and keep moisture in the soil. If you mulch, use clean organic material like organic grass clippings, seed-free straw or leaf mold. Spread an even layer 2 to 3 inches thick. Leave a clear circle around each butter lettuce plant 1 to 2 inches from the base.