Gourmet grown in a container

Containers open up new possibilities for gardeners who want to try their hand at growing some of their food. Starting with a small container for homegrown salad greens is a great way to make gardening a part of your everyday life and get your first taste of that garden-to-table experience.

Lettuce is one of the best vegetables to grow in containers, indoors or out. Growing lettuce outdoors in pots or boxes on doorsteps, porches, patios, balconies, and rooftops is easy. Lettuce can be grown indoors on a windowsill or under lights.

There are many excellent varieties to choose from, but there are four basic types:

• Head/crisphead lettuce (like iceberg lettuce) requires 80 to 85 days to mature. It has a tight, round head.

• Butterhead lettuce (known as Boston or Bibb) matures in 65 to 80 days. It forms small, open heads with soft leaves.

• Loose-leaf lettuce matures in 40 to 45 days. The leaves are loose and easily separated.

• Romaine lettuce (also called cos) matures in 70 to 80 days. It forms long, lightly folded oblong heads.

Grow leaf salad greens so you can harvest as needed rather than wait for a whole head of lettuce to grow. Loose-leaf lettuce varieties are the quickest to harvest.

Choose a container at least 6 to 8 inches wide and 6 to 8 inches deep for leaf lettuce. To grow head lettuce, you need a container that’s 16 inches wide and 12 to 16 inches deep. This will accommodate a mature lettuce plant and its roots. The length of the container is determined by the number of plants you want to grow. Some favorites are cedar, stainless steel, and terra cotta clay. Look for words like “food grade” or “untreated” to ensure you use natural materials. 

Be sure to add drainage holes to the bottom of your container if it doesn’t come with them. Your lettuce plants won’t be happy sitting in extra water.  

Cut a piece of weed barrier cloth and cover the drainage holes in the container. This ensures that the soil won’t run out of the container each time it’s watered or it rains.

Good soil is the secret to growing anything. Lettuce plants like a soil mix that’s a little more alkaline and nitrogen-rich. Use an organic potting soil and compost mixture. Creating a 50/50 mixture of soil and compost works well. Try growing lettuces in a sandy loam soil mix if you can find one. Fill the container nearly to the top.

Lettuce is a cool weather crop. Lettuce will go to seed in hot weather. Start outside lettuce containers in early spring or late summer to mature outdoors. Plants can be brought to maturity inside and moved outdoors when the weather is cool but not cold. Lettuce grown indoors can be planted at any time of the year. 

Lettuce can be started from seeds or transplant seedlings. You can buy pre-mixed seeds for baby greens or salad mixtures. You can purchase seedlings at a garden center or grow your own.

Use a dibber, wooden stick, or chopstick and measuring tape or seed spacer to ensure that the seeds are spaced three to four inches from one another in rows that are at least two to three inches apart. Gently cover the seeds with ¼ to ½-inch soil and lightly water.

Give the container at least four hours of sun daily and about one inch of water per week. Check the lettuce container each morning to ensure the soil doesn’t dry out as the seeds germinate. As you water, do not disturb the tiny seeds and seedlings as they begin to grow.

Test the soil’s moisture by gently sticking your fingertip into it. If it feels dry a few inches down, it’s time to give the plants a drink. If your container is shallow or in direct sunlight, you must water more often. 

As the seedlings grow, make sure to thin them out. Fortunately, you can eat all those baby greens, which will have a sweet flavor.

Feed your lettuce with a water-soluble fertilizer every two weeks. Fertilizer provides the plant with the nitrogen it needs to keep producing tender leaves. Follow the label directions for your fertilizer of choice.

You won’t have to wait long to start snipping your lettuce. In three to four weeks (depending on the variety), begin harvesting from your salad container by cutting each plant from the outer and lower leaves with sharp, clean scissors. By harvesting only the outer leaves, you can return the next week to harvest from the same plants. Continue to harvest as the salad plants keep growing. 

For a continuous supply of fresh lettuce throughout the growing season, plant new seeds or new transplants every three to four weeks to replace harvested and older plants. Do this by planting new containers or pulling out tired, spent lettuce plants and replacing them with new ones. 

Make sure to harvest everything before the lettuce flowers. Known as bolting, the lettuce will taste bitter after it flowers or goes to seed.

Lettuce tastes best eaten the same day it’s harvested. Wash the lettuce leaves thoroughly under cool water to remove dirt or debris. Dry the leaves completely before storing, as excess moisture can lead to wilting and spoilage. Use a salad spinner or gently pat the leaves dry with a clean towel. Wrap the dry lettuce leaves in a dry paper towel to absorb excess moisture and help prevent wilting. Store the wrapped lettuce in a plastic bag or an airtight container. Place the container or bag in the refrigerator’s crisper drawer, which is designed to maintain high humidity.

Growing salad greens can provide a source of fresh, leafy vegetables with the added benefit of trying varieties that may not be available at local markets. In addition to salads, leafy greens make flavorful and nutritious additions to sandwiches or wraps.

Sources: gardenary.com; growfully.com; uwyo.edu; uwyoextension.org. Vicki Hayman is the Community Vitality and Health educator at UW Extension Weston County. Contact her at vhayman@uwyo.edu.