Lettuce is a fun, economical vegetable to grow in the backyard garden. It's one of the few vegetables that can tolerate partial shade, and itís also one of the best vegetables to grow to save money on your grocery bill; an inexpensive package of seed can yield enough lettuce to double or triple your investment.
But all too soon, the lettuce harvest is gone. The weather turns hot, the lettuce turns bitter. It bolts, it wilts, and soon you have a bed of nothing more than fresh compost fodder. What's a gardener to do?
Fortunately, a few tricks of the trade can help you extend the lettuce harvest so that you may just be able to have the "L" on your "BLT" sandwich from your garden.

The Basics of Growing Lettuce

Lettuce is a cool-season vegetable. This means that it prefers cool temperatures, and when the warm, sultry weather arrives, it signals the plant that the season is done. Lettuce requires temperatures between 40 and 85 degrees F, preferably somewhere in the mid 50s and 60s in order to be happy.
Like many vegetables, lettuce prefers more sunlight than less, but it tolerates partial shade just fine. It does need moist, loamy soil in order to grow well. The soil doesnít have to be deep - six to 12 inches is fine. That's good news for balcony or patio gardeners, since you can grow lettuce in a window box, container or planter.
Sow lettuce seeds directly into the soil as soon as it can be worked in the spring. Itís a good idea to check with your local Cooperative Extension office for the proper planting times in your part of the country for lettuce and other vegetables. If this is your first year growing a vegetable garden, a soil test and consultation with your local Extension Agent is also a great idea. You can learn a lot from a soil test, and the expert will guide you on which amendments to use and in what quantity to improve your soil.
To plant lettuce, begin by moistening the soil if rain or melting snow hasnít already wet it enough. It's best to sow lettuce seeds directly in the ground. Open the seed package and gently tap it so that the seeds tumble to the ground. spaced about half an inch apart. Do not bury the seeds, but sprinkle peat moss or soil over the top of the seeds to a depth of just about a quarter of an inch. Water the newly planted seeds well, and keep the soil evenly moist during the growing season.
It's a great idea to stagger your planting times by about two weeks so that you don't have a huge crop of lettuce mature all at once. Lettuce stores for a few days to a week on average in the refrigerator, but after that, it's good for nothing except animal feed or compost. By staggering your seed planting time to every two weeks or so, you should be able to stagger the harvesting times, too, so that the lettuce doesn't all come in at once. No matter how much you love lettuce, you may get sick of eating salads if it all matures at one time.
If your soil has been amended with compost, it does not need fertilizer to grow a good crop of lettuce. You can sprinkle a little 5-10-10 fertilizer on the soil if you wish.
To harvest lettuce, gently tear or snip off the leaves with a clean, sharp pair of scissors. Wash them and enjoy them. You can also pull the plant up and chop off the roots to enjoy the entire head of lettuce.

Three Ways to How to Keep Lettuce Growing

Extending the lettuce harvest beyond the typical early to mid-spring window requires a little cleverness and ingenuity on your part, but most gardeners relish the challenge. Here are three ways you can coax a few more weeks of growing time from your lettuce:
  1. Plant lettuce seeds underneath tomato plants: One old-time trick is to plant lettuce seeds underneath tomato plants during the late spring or early summer months. As the tomato grows, the leafy green canopy of branches shades the soil, creating a little shady microclimate that may just be cool enough to prevent lettuce from bolting.
  2. Choose heat-tolerant varieties. Unfortunately, most of the popular store varieties such as Iceberg and Romaine thrive in cool weather, not hot. Experiment with loose leaf varieties. Oakleaf lettuce, which has a pretty form, is the most heat tolerant. Good varieties to plant later in the season include Red Sails, Black-Seeded Simpson, and all the Oakleaf varieties.
  3. Plant your early spring crop in the sun, your late spring and early summer crop in the shade. By choosing different planting areas, you're using nature's micro climate of shade and cooler soil to provide conditions more favorable to growing lettuce.
You can also grow lettuce indoors on a bright, sunny window or under plant lights. Youíll need a light setup similar to one used to start seeds indoors. Two to four fluorescent light bulbs on a shop light system should be sufficient to grow lettuce. You can grow a little flat of lettuce on a countertop this way or even in your basement. The best varieties to grow indoors are the loose leaf varieties including the Black-Seeded Simpson, Red Sails, Red Salad Bowl, and Green Sails varieties. Mesclun and arugula also grow well under lights. Some city gardeners also plant a few radishes alongside their salad bowl gardens for a delicious treat.
Fresh lettuce is easy to grow and enjoyable to eat. The longer you can grow it in the garden, the more you can enjoy it. Using these tips, you may be able to coax another two to three weeks of fresh-grown lettuce from your garden.