Guide to Growing LettuceAuthor: Beth Sears
Beth Sears has worked in the garden industry for 10 years--and grows fruits, vegetables and flowers in her Midwest garden.
Both beginner and experienced gardeners love growing lettuce because it's easy to grow and so rewarding. Lettuce can be grown almost anywhere. It fits into smaller gardens, raised beds, containers and even window boxes. It grows quickly. You can begin harvesting baby leaves just 30-40 days after sowing the seeds. Packed with nutrition, homegrown lettuce is tender, sweet and flavorful. If you want to add this plant to your garden grow your own lettuce, just follow this expert's guide to get started.
How to Grow Lettuce
Lettuce is a cool-season annual plant that is often grown in the spring and fall gardens. Gardeners can choose from an array of types, from the quick-growing loose leaf lettuce to romaine, iceberg and butterheads. To extend the harvest season, many gardeners sow lettuce seeds every few weeks.
When to Grow Lettuce
Lettuce grows best in cool weather or when outside temperatures are 60-70 degrees F. When to plant lettuce, for most gardeners, is in the spring and fall. Because lettuce seeds germinate at soil temperatures between 40 and 80 degrees Fahrenheit, you can sow lettuce seeds into the garden in the spring, about 4 weeks before the last spring frost date in your area. Some gardeners start lettuce seeds indoors and transplant them to the garden. To ensure a continual harvest for weeks, many gardeners sow lettuce seeds every two weeks throughout the spring. Other gardeners extend the season by growing lettuce in cold frames.
Where to Grow Lettuce
Lettuce grows best in full sun, or six to eight hours of direct sunlight daily. However, it can also be grown in partial shade. As the temperatures warm in the early summer, lettuce benefits from a bit of afternoon shade. Hot weather usually causes this plant to bolt. If growing lettuce for a fall crop, provide some afternoon shade in late summer. Many gardeners plant lettuce near taller growing plants that will provide some shade.
Lettuce performs best when grown in well-drained soil, rich in organic matter, and with a pH that is neutral to slightly acidic. Mixing compost or aged manure into the soil before planting can improve the soil. A soil test provides information on what amendments should be added to the soil. You can send your soil to a lab for testing or use home testing kits, such as the Soil Analyzer. Till the soil so that it has a fine texture. If it has lots of clumps, lettuce seeds will not germinate as well.
How to Plant Lettuce
If sowing lettuce seeds directly into the garden, plant them 1/8 to 1/4-inch deep. Lettuce seed needs light to germinate, so sow them shallowly. The spacing can vary. Some gardeners plant them 1-2 inches apart and then thin them. The distance between plants depends on the lettuce type. Loose-leaf lettuce should be spaced 4 inches apart while Romaine and butterhead types can be spaced 8-10 inches apart. Iceberg lettuce should be spaced 16-18 inches apart. Space rows about 18 inches apart.
Because lettuce seeds are so small and lightweight, some gardeners use seed tapes which takes the guesswork out of spacing. You don't have to worry about over seeding or under seeding.
If transplanting lettuce seedlings to the garden, follow the same spacing rule. Lettuce plants can be set out about four weeks before the last spring frost date for your area.
Water thoroughly at the time of sowing or transplanting. When the plants start growing, make sure the soil is moist, but not overly wet. Overwatering can make the plants more susceptible to disease.
How to Harvest Lettuce
Knowing when lettuce is ready to harvest depends on your harvest method. You can harvest lettuce in three different ways.
Lettuce can be harvested at the baby leaf stage often 30-40 days after sowing. Just harvest the outer leaves and let the inner leaves continue to grow. This is the most common harvesting method for loose leaf varieties, as well as butterhead and romaine types. You can also cut the entire plant about an inch above the soil surface. Some varieties come back after this and produce a second crop. You can dig up the whole plant, roots and all. If harvesting crisphead lettuce, cut the lettuce head off when the center is firm. For the most flavorful lettuce, harvest leaves and plants in the morning.
How to Grow Different Types of Lettuce
Gardeners can choose to plant loose leaf lettuce, romaine, butterhead or iceberg lettuce. Each is a little bit different to grow and harvest, and each has its pros and cons. Below is an overview of the lettuce types.
Growing Loose Leaf Lettuce
If you are looking for ease of growth and an early harvest, loose leaf varieties are the way to go. Available in shades of green, red, purple and bronze, loose leaf lettuce is ready for harvest in just 40-50 days. They grow about 8-12 inches tall and form loose heads. The leaves are excellent for salads and sandwiches. Some popular loose leaf varieties are Bronze Beauty, Green Ice Leaf and Red Velvet.
Growing Romaine Lettuce
Romaine lettuce, or Cos, usually has large, vase-shaped heads with dark leaves and creamy white hearts. The plants can grow 20 inches tall and usually take 60-80 days to reach maturity. Because romaine lettuce takes longer to mature, it's often started indoors and transplanted to the garden. The leaves add flavor and crunch to salads, sandwiches and wraps.
Growing Butterhead Lettuce
Butterheads, also called bibb or Boston lettuce, are known for their tender leaves and buttery flavor. They grow in loose heads and have dark green to buttery yellow leaves. Their height varies depending on the variety. Growing butter lettuce is easy, and the lettuce is ready for harvest in about 65 days. They can be directly sown into the garden or started indoors. A popular butterhead, especially in the South, is Little Gem.
Growing Iceberg Lettuce
Iceberg, or crispheads, are often more difficult to grow than other lettuce types. Because they have a longer growing season, they are often started indoors and transplanted to the garden. They usually take 80-90 days to mature. To avoid the hot summer days, many crispheads are planted as a fall crop.
Pest & Disease Control
Some of the most common insect pests are snails and aphids. To control slugs, you can handpick them or use a slug repellent. Super-Lite Insect Barriers are effective at keeping insects at bay. Monitor you lettuce plants for signs of insect damage.
Lettuce can also be affected by bacterial and fungal diseases, including bacterial leaf spot, downy mildew and damping off. Some preventative measures you can take are to avoid overcrowding and overwatering. Also, practice crop rotation. When using disease control products, make sure to follow label instructions.
Because it's fast-growing, easy to grow and delicious, lettuce deserves a spot in the garden--or a container. The key things to remember about growing lettuce are:
- It's a cool season crop that's easy to grow from seed.
- Sowing seeds every few weeks extends the harvest.
- Loose leaf lettuces are generally the easiest and fastest to grow.
- Lettuce grows in well-drained soil and full sun, but can handle part shade.
- Lettuce can be harvested at the baby leaf stage in 30-40 days.
The best way to get started is to choose a couple of lettuce seed varieties you'd like to grow. Then watch the 'How to Grow Lettuce from Seed' from earlier in this blog.
FAQs About Growing Lettuce
How long does it take for lettuce to grow?
Depending on the variety and harvest stage, lettuce can be ready for harvest in 40-80 days.
Does lettuce need full sun?
While lettuce prefers full sun, it can be grown in partial shade.
When is lettuce ready to harvest?
If harvesting at the baby leaf or leaf stage, it can be harvested about 30-40 days after harvest. If growing buttercrunch, romaine or iceberg lettuce, you can wait until heads form before harvesting.