Learning how to grow lettuce can be very rewarding.
Contrary to its image of being boring and flavorless, the world of lettuces is full of color, texture and taste. Homegrown lettuce is a delight and you can enjoy a cool, crisp bowl of salad made from an array of different lettuces in your garden. Lettuce is a favorite because it is relatively easy to grow, is one of the first crops that can be planted and is one of the first crops to yield in the spring. It doesn’t take a lot of room and because of its shallow root system it does well in containers too.
There are mainly five types of lettuce:
Crisphead: Generally the most difficult type of lettuce to grow, mainly because they require a long, cool season to mature. Crisphead varieties are ready to harvest approximately 95 days after sowing the seeds. In most of the U.S., one needs to start planting indoors during late winter to succeed in growing a good crop of crispheads.
Cos (Romaine): Romaine lettuces also require a fairly long cool season, 70 to 75 days until harvest. Gardeners in areas with very short cool seasons should start the seeds indoors. However, romaines have a distinct advantage over crispheads, because the outer leaves of the head can be harvested as it continues to grow.
Butterhead: The most well-known is the butterhead variety of lettuce, also known as 'Boston Bibb.' Butterheads are famous for their smooth (buttery) texture. They form loose heads, which mature 55 to 75 days after sowing. However, it’s possible to harvest the outer leaves earlier, as new leaves will grow from the middle of the rosette.
Looseleaf: These lettuces are the easiest to grow. They can be sown and harvested within a few weeks, as tasty baby lettuces. Looseleaf variety can be harvested by picking or cutting leaves from the plant. New leaves will form, and by sowing fresh seeds every couple of weeks, the quantity can be increased.
Batavian: Batavians are probably the least known type of lettuce. They can be sown and harvested like looseleaf lettuces, but mature into crisp round heads fairly quickly, making them ideal for gardeners who enjoy crisphead lettuces but have a shorter cool season. Batavians are ready to harvest (as heads) 55 to 60 days after sowing.
Lettuces require at least 6 hours of sunlight per day. In a very warm climate or heavy summers in which temperatures frequently reach the mid-eighties, the planting site needs to be protected from the afternoon sun. This can hold off the bolting that is brought on by hot weather. If this isn’t possible, consider installing a shade screen over the area.
Lettuces also need loose and rich soil to grow well, such as soil that has been well amended with compost or rotted manure, which is ideal. Soils with plenty of organic matter retain moisture better, which is very important in keeping these shallow-rooted veggies happy.
If the garden has poor quality soil, consider building a raised bed and filling it with a mixture of topsoil, manure and compost or plant the lettuce seeds in a container that is at least four inches deep. In general, lettuce is a light feeder, so an initial application of fertilizer is probably all that will be needed. A soil pH of about 6.0 to 7.5 is preferred.
How to plant:
1. Buy lettuce plants at the nursery when night-time temperatures stay above 30 degrees Fahrenheit. Otherwise, sow seeds directly outdoors as soon as the soil can be worked in spring.
2. Till the soil thoroughly, breaking up soil clumps and removing stones and other debris. (Lettuce seeds are tiny and any obstacle can hinder germination).
3. Set plants 8 to 16 inches apart, depending on the variety. When in doubt, err on the side of distance – crowded plants and poor air circulation invite disease and insect problems.
4. Keep the soil moist, but avoid watering in the evening. Foliage that stays wet overnight is prone to disease.
5. Mulch to conserve moisture and keep the soil cool, and feed it every three weeks with seaweed extract or compost tea.
6. Ensure a full season’s worth of greens by making successive sowings 10 days apart and by choosing heat-resistant varieties for late-spring plantings and cold-resistant ones for harvesting well into fall.
7. Begin cutting leafy lettuces as soon as they’re big enough to use. Harvest the head types when the heads are firm and fully formed.