When to Plant Lettuce: Ultimate Growing Guide

Understanding when to plant lettuce ensures your success with this cool-season superstar. Lettuce grows easily in garden beds, containers, or any compact urban environment. Timing matters because planting too late can lead to bolting, where your plants become bitter and woody. This is a lesson I learned in my early gardening endeavors, losing a spring crop. Get your timing down for consistently crisp lettuce harvests!

With careful selection of varieties and the use of season extenders, you can enjoy fresh lettuce throughout the year. Some types of lettuce, such as Arctic King, can overwinter easily with just a row cover. Others, like Jericho Romaine, are heat-tolerant and will produce during the summer heat. If you are a beginning gardener, loose-leaf types are a great starting point since they are forgiving of mistakes and grow quickly. Each harvest will boost your confidence.

Looseleaf varieties, such as Oakleaf and Salad Bowl, are at their best in the spring and fall while growing and tolerating light frosts at temperatures between 50-65°F (10-18°C). The open growth habit allows you to harvest the outer leaves multiple times. These are perfect for quick salads, as they can be harvested in just 30 days' time from seeding. All of the produce that can be relied on during sudden temperature changes throughout the season is the looseleaf varieties.

Crisphead varieties such as Iceberg require perfect timing. Plant them early in spring when the soil temperature is 45-55°F (7-13°C). They develop the most tightly formed heads before the summer heat sets in. I grow these in my seaside garden for early-season crunch. They are slow-maturing and require a long wait, but deliver a refreshing crunch.

Summer demands heat heroes such as Jericho romaine and Sierra Batavia that resist bolting to 85°F (29°C). You can plant these when nighttime temperatures stay above 50°F (10°C). I use 40% shade cloth on these for even longer harvests. Their leaves are thick enough to combine with dressing and not wilt.

Winter champions are Arctic King and Winter Density. They stand up to freezing temperatures under simple protection. Seeds are started in early fall to provide harvests under snow. In my unheated greenhouse, they provide fresh greens through the cold winter months. Their cold, sweetened leaves have excellent flavor that can't be beat.

Plant lettuce when soil temperatures have reached 40°F (4°C) in early to mid-spring, about 4-6 weeks before your last frost date. Use floating row covers if a cold snap occurs below 50°F (10°C). Northern growers will want to ensure the soil has thawed completely. In contrast, southern growers can seed earlier with loose-leaf lettuces, such as Black Seeded Simpson.

For planting in summer, plant after your nighttime temperature consistently stays above 50°F (10°C). When temperatures exceed 75°F (24°C), use a 40% shade cloth. Look for heat-tolerant varieties, such as Jericho romaine. For southern gardeners, elevated containers can help increase air circulation around the roots.

In terms of timing, fall planting typically begins 8 weeks before your first frost, when the soil temperature drops below 70°F (21°C). Use low tunnels when nighttime temperatures fall below 40°F (4°C). Cold-hardy types, such as Winter Density, thrive in this environment. Coastal areas can get a 2 to 3 week longer season with protection.

Winter planting requires fall sowing before the ground freezes in mild areas, in unheated greenhouses, or without direct cover once the temperatures drop below freezing; the Marvel of Four Seasons grows well under these conditions. Residents further North require insulated cold frames, whereas mountain gardeners need a south-facing planting area for optimal sun exposure.

Opt for direct seeding when planting looseleaf varieties such as Oakleaf. Spread seeds 1/4 inch deep (6 mm) in prepared beds. Thin later, spacing plants 2 inches apart (5 cm) in the first sowing. This technique is ideal for succession planting, but uneven germination can occur, especially if the soil is crusty. I like it for fast summer crops.

Transplanting is ideal for types like Iceberg. Start seeds indoors for 4 weeks before planting outdoors. Transplant at 8-12 inches (20-30 cm) spacing. Handle seedlings by leaves, not stems, to avoid injury. Transplant provides earlier harvests, but be sure to harden off properly.

Master seed handling through these tips. Use dry fingers or tweezers for small seeds. You can also mix the seeds with sand for even dispersal. Maintain a soil surface temperature of 60 to 65°F (16 to 18°C) for optimal germination. Use burlap to cover new seed beds, retaining moisture and preventing evaporation.

In summer, water lettuce should be watered deeply three times a week, and the watering frequency should be reduced to twice a week in cooler weather. Use dripper or soaker hoses to minimize leaf wetness, which can lead to fungal disease. Test soil moisture 2 inches deep (5 cm). Sandy soils require more frequent watering. Steady moisture prevents tipburn during head development.

Use balanced 10-10-10 fertilizer at the time of planting (use 2 lbs per 100 sq ft). When the plants are 4 inches (10 cm) tall, use a nitrogen-rich fish emulsion every three weeks. Container lettuce requires a liquid seaweed tonic every two weeks to maintain optimal nutritional levels. Avoid over-feeding, which will lead to soft heads.

Organically manage pests. At dusk, apply iron phosphate bait for slugs and snails. To eliminate aphids, spray them with a mixture of soapy water, using 2 teaspoons of soap and 1 quart of water. Create barriers of copper tape around beds. Use reflective tape for birds. Incorporate ladybugs into their habitat if they have aphids.

When defending lettuce against temperature extremes, use season-specific tools, shade cloth (40%) above 75°F (24 °C). Row covers below 40°F (4 °C). Burlap screens for wind. Plastic tunnels for heavy rain. These tactics will give you an advantage for a much longer growing season.

Succession planting provides a continuous supply of lettuce when planting occurs at 7-14 day intervals. No glut or gap in supply is too overwhelming. I use this method to harvest fresh greens for six months of the year! It makes maximum efficient use of garden space and provides a little backup in case a crop fails.

In the spring, be sure to plant every 7-10 days. When the weather is hot in summer, plant every 14-21 days. In the fall, the rate is expected to return to 10-14 days. The winter months include one planting in the fall, which requires protection from the elements. In the southern gardens, fall planting can be extended until December.

Rotate crops according to temperature variations. Start with cold climate-tolerant Winter Density in early spring, then move to heat-resistant Jericho romaine in late spring. Use Sierra Batavia only in mid-summer. Finally, in the fall and winter months, use the cold-hardy Arctic King.

Follow this sowing schedule for best results. Start with cold-tolerant types from March 1 to 15. Switch to butterheads April 15-May 15. Start heat lovers June 1-July 15. Initiate fall varieties from August 1 to 30, plant winter lettuce from September 1 to 15 for cold-season hardiness.

When you select your varieties wisely and use some simple protections, lettuce will give you harvests every season. The frost-tolerant Arctic King can withstand snow as long as it is under row covers, and Jericho romaine excels in summer heat. This is why lettuce is great for new growers. Start with looseleaf varieties for dependable success. Your first harvest can lead to more confidence in growing.

Succession planting turns intermittent harvesting into a blended feast. If you sow small amounts every 7-14 days, Parisienne-type lettuce will never leave your table. I grow enough for salads and often for cooking greens for six months with this method. I also saw a variety once, again, with succession planting in mind. It's optimal with some variety rotation if you want the best. Experiment with different variables, utilize seasonal planning to your advantage, and discover what works within your geographic range, climate, and your own garden.

Experiment freely with techniques, try container growing on patios, and consider cut-and-come-again harvesting. Keep track of what different varieties can do in your microclimate. Gardening becomes a fun and joyful endeavor when you experiment through trial and error. Share your findings with other gardeners. The process will bring you the best, crispy rewards and satisfaction from your efforts.