a guide to growing lettuce

Growing Lettuce: Useful Guide for Planting at Home

Last Updated on August 16, 2022 by Real Men Sow

Growing lettuce is as easy as 1-2-3. It is considered a spring and autumn crop that thrive in cool temperatures. Sow lettuce seeds early enough to ensure plants are ready for harvest in cool weather. Bolting can be stopped by picking the oldest leaves first, but this is not possible. Lettuce that bolts can be bitter-flavored so harvests lettuce as soon as the weather cools down.

There are many types to choose from when it comes to lettuce: butterhead, Bibb, and looseleaf have a loose texture with a loose head. Romaine and Cos have elongated heads; crisphead, and iceberg have a head that is tightly folded. Lettuce matures between 40 and 80 days depending on what type of lettuce you planted. Looseleaf takes 40 days, butterhead takes 40 to 70 days, and romaine or iceberg takes 80 days.

Tips on Sowing and Growing Lettuce

Lettuce can be grown from seeds or transplants. You can start lettuce indoors four weeks before transplanting. Once the soil is ready, sow or transplant the lettuce into the garden. The seed germinates within 2-10 days at 70°F (21°C). However, it can sometimes take up to 2 weeks if the soil temperature is too cold.

To ensure that seeds germinate, keep the soil well-watered. Then, make sure to keep the soil moist until the seedlings are established. Seed 1/4 inch to 1/2 inch (6-13mm deep). Start seeds four inches (10 cm) apart. Later, thin the seedlings according to type: leaf, 6-9 inches (15-23 cm), head, 10-12 inches (25-30 cm), apart. To avoid diseases, ensure that there is adequate air circulation around mature plants. Plants should be spaced 10 inches (25cm) apart for intensive planting.

Lettuce thrives in full sunlight but can be grown in light shade. The ideal growing temperature for lettuce is between 40-75°F (4-24°C). Lettuce likes soil pH between 6.8 and 6.0. Pre-sowing your garden beds with aged compost is a good idea. It will help retain moisture and feed the soil.

Avoid planting lettuce in areas where radicchio or endive, escarole, or artichokes recently grew. For a longer harvest, sow successively every few weeks. Fertilize at half strength with organic fertilizer, such as fish emulsion.

Growing Lettuce Calendar

For Spring Harvest

Direct-sow in a cold frame or plastic tunnel for 10-8 weeks prior to the last frost in spring. Direct sow in your garden 4-6 weeks before the last frost in Spring. For continuous harvest, sow succession crops every 3 weeks; bolting will occur in hot weather.

For Fall Harvest

Direct-sow seedlings in the garden 8 to 6 weeks before the first fall frost. 4 to 6 weeks before the first frost of fall: Sow or transplant seedlings in a cold frame or plastic tunnel for winter harvest and fall.

Tips on Growing Lettuce 

Lettuce thrives in sunny, cool locations. These plants can be planted in spring, mid-summer and early fall. However, you can still grow it in summer in warmer regions if your varieties are heat-tolerant and bolt resistant.

Some lettuce cultivars are ready to pick in as little as 45 days, while others take twice that time. Lettuces range from leaf lettuces with no heads to lose-heading butterheads and tight-headed crispheads.

Planting Lettuce Location

Site

Cool conditions are ideal for growing lettuce in full sunlight. You should have a site that gets four to six hours of direct sunlight each day. Lettuce needs afternoon shade in hot regions.

Soil

Average soil is best for lettuce, but sandy loam works well. To prepare the garden bed, till or dig to 4 inches, remove large clumps of organic matter, then add an inch or more of compost. If the soil is heavy or slow draining, plant lettuce in raised beds.

Temperature

Lettuce thrives in cool temperatures, between 60°F and 65°F. If you want to grow lettuce in higher temperatures (especially 80°F) make sure that your planting area gets afternoon shade.

Warm-weather growing lettuce

Plant heat-resistant lettuce varieties where it is warm. Bolting can be prevented by water and shade.

Lettuce Seed Starting and Transplants

Seed Starting

65°F is the ideal temperature for germinating lettuce seeds. For lettuce seeds to germinate in warmer temperatures, sow the seeds in a small trench in the morning. Water the seeds and cover the row with a board. To check for germination, lift the board each morning. Remove when the seedlings begin to dig into the ground. Pre-sprouting seeds in warm soil can improve germination.

Transplanting and Spacing

For butterhead varieties, thin or transplant lettuce seedlings at 7 to 8 inches spacing, for loose leaf cultivars, and for romaine varieties, at 12 to 15 inches spacing. In warm weather, shade cloth placed over a frame can protect seedlings from the cold.

Succession Planting

To ensure fresh lettuce, plant successively every three weeks.

Caring for Growing Lettuce

Water

Lettuce needs moist, but not soggy, soil. The crop should receive at least one inch of water per week. This is approximately 1/2 gallon for each plant. Too much water can strip nutrients from the soil, causing lettuce leaves to turn yellow. To green up your plants, add 15-10-10 fertilizer.

Feeding

Lettuce, and other leafy crops, require a lot of nitrogen. To ensure rapid and steady growth, feed lettuce once or twice a year with fish emulsion or manure tea.

Mulch

To conserve soil moisture and weeds, mulch plants at 4 to 6 inches high with a 2-inch layer of aged compost. Leaves will remain clean. Make sure that the mulch is not too close to the crown of the plant. Mulching close to the crown can lead to plant rot.

Disease Prevention

Water lettuce early in the morning to prevent fungal diseases. Water lettuce early in the morning to make sure that moisture is vaporized from the leaves throughout the day, and is dried by the evening.

Bolting

Bolting (going into a seed) can make lettuce bitter and it is possible when lettuce begins to lengthen. This can happen in a matter of days. Prevent this by pinching off the top of the lettuce or gently wounding the roots with a sharp spade. 

Harvesting Lettuce

Lettuce tastes best when picked in the morning. You can harvest loose-leaf varieties cut-and-come-again, trimming the leaves from the outside. The heads should be firm when harvested. To check for firmness, press each head with your back to verify. Remove heads below the lower leaves by using a sharp knife or pulling the plants from the roots.

Problems on Growing Lettuce: Troubleshooting

For best growth, most varieties of lettuce need cool weather or light shading. Plant lettuce in the cooler part of the year when temperatures are between 50 and 60°F and plant them as soon as the ground is ready to be worked in spring. 

Lettuce thrives in well-drained, average soil. For the best flavor, don’t crowd lettuce. Let it grow slowly and steadily. Poor soil or lettuce that has been crowded will make it bitter-tasting and difficult to grow.

Wilting and Collapsing

Seedlings wilt and collapse with dark water-soaked stems as soon as they appear

Damping-off is caused by a fungus living in soil, especially where humidity is high. Avoid planting in moist, cold soil. It is important to ensure that the soil is properly drained.

Young stems chewed

Young earwigs eat leaves and shoots. The infestation is usually mild and tolerable. To catch earwigs at nights, traps made of rolled and wet paper or old flower containers stuffed with paper can be used. Wash them with soapy water. Keep your garden clean of all plant debris. Use garlic and hot pepper repellent to spray the garden.

Leaves Distortion or Curling

Leaves are distorted or curled under with small shiny specks

Aphids are small, oval-shaped, yellowish to greenish-pear-shaped insects that live under leaves. Honeydew, a sticky substance that can become a sooty mold, is left behind by aphids. Use water to blast the aphids out. Use insecticidal soap. Mulch with aluminum foil to disorient aphids.

Scorched and Wilted Leaf Margins

Leaf margins appear scorched and wilted

Leafhoppers can be green, brown, or even yellow and are about 1/3 inch in length. They have wedge-shaped wings and are wedge-shaped. They consume the juices of plants. Use insecticidal soap. To keep leafhoppers away, cover plants with floating row covers.

Silver Slime on Leaves

Trails of silver slime on leaves or leaves eaten.

Leaves are the main food source for slugs and snails. Keep gardens clean and free from debris to reduce hiding places. As a shelter trap, handpick the plants from the underside of the board. To attract and drown snails or slugs, use a shallow tray of beer with a lip at ground level.

Small ragged holes eaten in leaves

The cabbage looper caterpillar is a light-green, yellow-striped caterpillar that walks in a loop. Keep your garden free of any weeds or debris that could attract brownish-colored night-flying moths, which can then lay eggs. To keep moths away, cover plants with spun polyester Hand pick loppers

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