Lettuce is a popular crop that is easy to grow. It is annual, which means it will not re-grow each season. If you eat a lot of salads or are looking for ways to eat healthier, you can save money by growing them in raised garden beds or containers. You can also grow lettuce in pots, tiered wooden planters, or on balconies. In addition to being used for salads, they can be used in lettuce wraps, in sandwiches, and in coleslaw. There are hundreds of varieties of lettuce, which can generally be placed in four categories: looseleaf, butterhead, crisphead (iceberg), and romaine. Below are several types of lettuce and their properties.
- Butterhead: Also known as Boston or Bibb, Butterhead forms loose, soft heads of lettuce. Bibb is the more expensive variety and often sold in plastic containers to protect its delicate leaves.
- Looseleaf: Among the easiest to grow, it forms heads in just 5 – 6 weeks. It has a mild flavor and an uneven ruffled surface. Its broad leaves and sturdy rib make it a good choice for lettuce wraps.
- Oakleaf: The leaves are shaped like oak tree leaves, and can be red or green in color, depending on the variety. Although it can be mistaken for a loose-leaf lettuce, its leaves are shorter and squatter and have a softer texture. Due to its more delicate leaves, Oakleaf lettuce is great for lettuce beds with other ingredients as the focal point.
- Romaine: With its tight, upright leaves, Romaine lettuce is stiffer than most varieties, with a crunchy center rib. Most romaine lettuce takes 60 – 80 days to harvest and is a popular choice due to its heat tolerance. It is an essential ingredient in traditional Caesar salads.
- Summer Crisp: Similar to Looseleaf varieties, it has more rounded heads. Summer Crisp is relatively tolerant of heat, making it suited for summer growing.
- Iceberg: It has large, tightly packed leaves, which makes it very crisp and watery. For best results, plant it during the Fall as it is sensitive to heat. It is often used in a chopped salad or wedge salad. You can also shred it into pieces and add it to tacos or wraps for a cool, crisp taste.
How to Grow Lettuce Plants
When: Lettuce is a cool weather plant that is best planted during early Spring or Fall. If you want an earlier crop, you can start planting seeds in doors 4 – 6 weeks before the last frost date. Although seeds can be planted after soils reach 40°F, seeds will grow best at 45 – 65°F. Lettuce transplants should be planted after the last frost date. To ensure a continuous supply, sow additional seeds every 2 weeks after initial planting. This prevents the lettuce plants from overcrowding, and you won’t end up with an overabundance of lettuce.
Where: Lettuce can be grown in raised garden beds or containers. You should plant your lettuce plants in a place that receives at least six hours of sunlight, as long as it is not too sunny or hot. If you are planting lettuce during the summer or in warm planting zones, you can place them in partial shade. To maximize efficiency of your harvest, plant it next to warm season vegetables, such as tomatoes, which will be able to take over the space afterwards. The soil should be loose, well-drained soil that is moist without being soggy. It should contain organic matter and have a pH between 6 and 7. To enrich the soil with organic matter, add in compost prior to planting. To improve soil retention, you can amend the soil with either vermiculite or perlite. If you are using a container, make sure it is at least 6 inches deep and 10 inches in diameter. Make sure the container has drainage holes at the bottom to prevent plants from becoming waterlogged.
How: Seeds should be planted at of depth of ⅛ or ¼ of an inch deep to allow light, with about 10 seeds per square feet. Seedlings can be thinned when they have 3 – 4 leaves. For both seeds and transplants, the rows should be 12 – 15 inches apart. For loose-leaf lettuce, thin to 4 inches apart, while for romaine and butterhead, thin to 8 inches apart. For crispheads, thin to 16 inches apart. You can consider planting companion plants such as chives or garlic to deter pests such as aphids.
Care: The watering requirements for lettuce should be light, frequent, and consistent, making sure to keep the soil moist. It is not necessary for it to develop deep root systems, as the leaves are an important aspect of the plant. Make sure to not water the leaves, which can cause them to rot. To promote leaf growth, use a fertilizer high in nitrogen around approximately three months after planting.
If you find your lettuce plants start to curl and brown, it may be suffering from tipburn, which is a physiological disorder characterized by a breakdown of the leaves of the lettuce. Tipburn stems from a calcium deficiency, as well as inadequate watering. To remedy this, trim the browned parts and begin a regular watering schedule. You can also try calcium foliar sprays to increase the calcium content.
A common pest for lettuce is aphids, which can easily destroy a lettuce patch, causing the leaves to wilt and curl as they siphon away nutrients. As there is no insecticide for aphids, you may find it helpful to plant the crops mentioned above, or find ways to encourage beneficial insects, such as ladybugs, which prey on aphids. Other common pests include slugs, snails, and caterpillars. They can be dealt with using traps, organic bait, or handpicking and disposing of them.
Bolting: When the soil becomes too dry, lettuce will start to bolt, which means it starts producing a central flower stalk. This causes the leaves to become bitter and inedible. Warm temperatures or dry conditions are common causes of bolting. To prevent bolting, cover your plants with a shade cloth, which will filter out sunlight. Also plant lettuce along with taller plants, which will shield them from sunlight.
How to Harvest Lettuce
Most lettuce can be harvested between 30 – 70 days after planting, with the precise time depending on the variety. For flavor and tenderness, harvest them when they reach full size, just before maturity. It is easy to harvest lettuce. You can remove a few outer leaves from the plant, which will allow it to produce more leaves, or you can cut off the entire bundle off the ground. Lettuce should be harvested during the morning before the leaves have been exposed to sun, which helps retain their crispness. Rinse immediately after harvesting and store in an airtight plastic bag. It can be stored in the refrigerator for up to 10 days.
If you have leftover lettuce, you may want to try to regrow it in small containers at home. While the yield is smaller, it is an interesting process and can still be enough for a sandwich or wrap.
- Cut off the leaves, leaving one to two inches intact from the bottom. Remove the leafy portions without cutting into the stem.
- Place it into a shallow dish of water and leave by a window.
- Change the water every couple of days. You may notice roots start to form.
- After about 10 – 12 days, which is likely the maximum height it will grow, you can chop the leaves off. Otherwise, they will degrade and become spindly and bitter.