Growing Lettuce

Why do so many of us put up with bland, flavorless lettuce from the grocery store? Not only does supermarket lettuce have to travel thousands of miles to make it onto our plates, it’s usually nutritionally devoid and filled with little besides water. When you compare it to the abundant varieties, textures, and flavors of growing lettuce at home, you’ll be ready to give up this pathetic substitute for good.

Homegrown organic lettuce has an incredible flavor you simply have to taste to believe. Full of beneficial nutrients and antioxidants, garden lettuce varieties are the perfect vegetable to incorporate into your healthy diet. Best of all, lettuce is so easy to grow. With a little work up front you can guarantee that you’ll be eating tasty salads all summer long.

Lettuce grows to maturity within six to eight weeks. This makes it an easy vegetable to grow with kids or in small gardens. Whether you choose to grow a full bed, plant some in containers or simply tuck a few lettuce plants in with your garden flowers, growing organic lettuce is well worth the effort.

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Start Growing Lettuce

You can start lettuce from seed either indoors or outdoors, depending on the time of year you are planting it. The following tips will teach you what you need to know.

When and Where Should You Grow Lettuce?

Lettuce is easy to grow in most conditions, so long as you don’t allow the young plants to get too hot. Try to give your lettuce about six hours of sun a day; any more and they might go to seed (bolt) prematurely. Organically rich, loose garden soil is essential for growing healthy lettuce heads. Make sure to keep your garden beds full of organic compost that is easy to access for the shallow roots of your lettuce plants.

If your garden has low-quality soil, planting your lettuce in raised beds or large containers can be a good solution.

Understanding Seed Germination for Lettuce

Lettuce grows from small seeds that have about an 80 percent germination rate. This means that a small seed packet can produce about 80 heads or fifty pounds of leaf lettuce. Seeds don’t tend to last long, so you should expect dramatic decreases in the germination rate of any seeds you plant that are older than a year.

Starting Seeds Indoors

You can start your lettuce seeds indoors about eight weeks before your last frost date. Use a sterile seeding mix to start the seeds and keep them in relatively cool temperatures, about 70 degrees F. You should plant about two seeds per container or growing cell, and thin out the weaker ones once the plants have four true leaves. A source of light is essential, either from a sunny window or from artificial grow lights.

Preparing a Lettuce Bed

To grow effectively, lettuce needs to be planted in garden beds filled with organic material and soil that allows for good drainage and that is full of nitrogen. A pH level between 6.0-6.8 is ideal. Nitrogen is essential for robust leaf growth, so feel free to amend your bed with blood meal or compost tea before planting.

Moving Outdoors

Once the last frost date has passed and your lettuce plants have several true leaves, they are ready to make the transition to the outdoors. First, harden off your seedlings by restricting their water and temperature for a few days so that they can better face the inconsistent conditions outdoors.

To plant your transplants, dig holes that are about twice the size of the lettuce root ball and gently place the plant in the hole, packing soil up around it. It’s important to be careful during this stage because lettuce tends to be more delicate than other garden plants. Space your head lettuces about a foot apart and loose-leaf lettuces about six inches.

Direct Seeding

To get an extra early lettuce crop, you can sow seeds directly into a cold frame or high tunnel about six weeks before the last frost date. If you only plan to grow your lettuce outside, you will need to wait until after the last frost date instead.

When your garden bed is prepared, you can broadcast your seeds or plant them a quarter inch deep at four inch spacing in rows spaced a foot apart. Cover the seeds with a quarter inch of compost and water them in place. Once the plants are about four inches tall, you can thin them out to twelve-inch spacing. The thinnings you pull out make a great addition to any salad.

Tip: The best way to ensure that you have lettuce that’s ready to harvest all season long is to plant it in successions. Follow the advice of Thomas Jefferson and plant a small number of lettuce seeds every Monday throughout your growing season to ensure you will have mature lettuce ready whenever you need some.

Watering and Mulching Requirements

Once your lettuce has been planted, the most important thing that you can do is keep it hydrated. The lettuce plant is about 95% water, and its shallow root system means that it can only pull water from the top few inches of soil. To avoid this, water your plants several times a week in hot weather. Less than an inch a week can cause the leaves to become thin and bitter or even cause the plant to bolt prematurely. If you can stick your hand into the top inches of soil and it comes out dry, your plants need more water.

Providing your lettuce with a nitrogen-rich fertilizer throughout the growing season will help it to continue to grow well and produce robust leaves. You can help retain both water and nutrient levels in your lettuce bed by mulching around your plants. A two to three-inch layer of organic mulch material like wood chips or chopped leaves will keep your soil cool and reduce the number of weeds competing for the garden space.

Companion Planting and Rotation Considerations

Lettuce grows well when paired with root vegetables like garlic, onions, carrots, and radishes. There aren’t any vegetables that cause lettuce plants to suffer, but it’s a good idea to rotate your lettuce beds so that you aren’t planting it in the same spot any more than once every three years in order to stop the spread of soil-borne disease.

Common Pests and Diseases for Lettuce

Some of the worst damage that your lettuce crop will face will most likely come from four-legged creatures like rabbits and groundhogs. Building a sturdy fence can help to keep these hungry creatures away.

Insects like slugs, aphids and cabbage worms can also cause damage. Check your plants every few days and pull off any slimy pests that you see eating them, or introduce some ladybugs into your garden as a natural predator for the aphids. Organic pest-deterrent sprays can also be used to keep a particularly bad infestation in check.

Soil that stays too wet can cause your lettuce to suffer from bottom rot, which causes the leaves to turn black, slimy and smelly. Give your plants plenty of breathing space and water them only on sunny mornings to ensure that leaves have plenty of time to dry out before night time.

Harvesting and Storing Lettuce

You can start harvesting your lettuce leaves when the leaves are about 6 inches long. This gives the plant enough time to get strong and survive the removal of its leaves. It’s best to use your hand to tear off the outer leaves and gradually move inwards as the season progresses. Always harvest lettuce in the morning when it is most crisp, and quickly store it in a refrigerated environment to preserve the maximum freshness.

To harvest a whole head, simply cut it off the root with a sharp knife about one inch away from the soil.

Once the leaves are harvested, you can rinse them thoroughly with water and shake or spin them to remove the excess moisture. Store the leaves in breathable plastic bags in the refrigerator and eat them within two weeks of harvesting.

Saving Lettuce Seeds

Lettuce seeds are fairly easy to save, so long as you prevent your plants from cross-pollinating with each other. Lettuce plants form seeds by “bolting” and creating long flower stalks from the center of the plant. Watch your plants while they are bolting and select one of the biggest and latest to bolt as the one to collect seeds from (late bolting is a desired trait) and allow the yellow flowers to turn into seed pods. It’s sometimes helpful to stake up your plants to prevent the seed pod from tipping over.

12-24 days after flowering, your seeds will be ready to harvest. Gather the dry seeds in a paper bag and crush them in your hands until the chaff separates from the seeds. You can store these seeds in a cool dry place for a year or two, but no longer as they will quickly lose their ability to sprout.

Choosing the Best Lettuce Seeds for Your Conditions

There are lots of different types of lettuce you can grow, and each variety has its own unique character traits. Below are some of the most common types of lettuce and some of the specific varieties you can grow.

Crisphead: Iceberg lettuce and Batavia are common types of this lettuce, which is known for growing into tight balls similar to a cabbage. Crispheads are some of the most difficult types of lettuce to grow because they need long, cold seasons to reach full maturity. For the best chance of success, plan on starting your crisphead lettuce indoors in order to get a jump on the growing season.
Cos (Romaine): This type of lettuce forms dense, upright heads with tender centers. Like the crisphead, romaine lettuce needs a long cool season to grow to success, though you can harvest the outer leaves while it’s growing in your garden.
Butterhead: Butterhead lettuces form loose heads made up of leaves renowned for their smooth, buttery texture. You can harvest the outer leaves throughout the season or simply harvest the entire head. Because butterheads are so fragile, they don’t travel well and rarely are available in grocery stores.
Looseleaf: As the easiest form of lettuce to grow, looseleaf varieties tend to be harvested at the baby stage and end up in salad mixes. You can shear off the leaves with a knife to make a salad, and most beds will allow you to get multiple cuttings from them.

Additional Growing Tips for Lettuce

There are lots of strategies for growing a great lettuce crop. Here are some extra tips to get you started.

Lettuce seeds don’t tend to last long, so it’s a smart idea to replace your seeds every year or expect germination of less than 50% on seeds over a year.
Get a big jump on your lettuce growing season by starting your plants in a cold frame or plastic high tunnel.
Make your loose leaf salad bed more flavorful by planting in some dill, cilantro, and other tasty herbs.
You can prevent lettuce heads from bolting in the heat by building them a temporary shaded area with old bed sheets.
If you have a small growing space, try growing some miniature lettuce varieties like ‘Minetto‘ or ‘Tom Thumb‘.
Plant new lettuce seeds every week or so, and harvest your heads when conditions are good, as lettuce can bolt in a matter of hours.