Lettuce
Lettuce thrives in sunny locations with 5 to 6 hours of sunlight but appreciates afternoon shade in hot weather. The soil should be moist and loose, well-drained, but not waterlogged. Enrich the soil with compost before planting for added fertility.
Crop Rotation
Lettuce matures quickly, making it a great choice for intercropping with slower-growing crops like corn or leeks.
Planting Time
Ideal soil temperatures for lettuce range from 45°F to 65°F (7°C to 18°C). Cold-tolerant varieties can withstand lower temperatures. Start sowing under cover in late winter for an early harvest, then sow outdoors from early spring. Direct sowing is best, about 2 to 4 weeks before the last winter.
Sowing Lettuce
You can sow directly into prepared soil or module trays filled with multipurpose potting soil. Remove weeds, rake the soil to a fine texture, and mark out shallow drills 8 to 12 inches (20 to 30cm) apart for direct sowing. Sow the tiny seeds in clusters every four inches (10cm), then backfill the drills, label them, and water them.
Planting Depth and Spacing
Plant seeds 1/8 to 1/4 inch deep, because they need light to germinate. You can sow in single rows or broadcast for wide-row planting. Thin seedlings to the proper spacing when they are 1 to 2 inches tall. The spacing depends on the variety: 4 inches for loose-leaf, 8 inches for romaine and butterhead, and 16 inches for crisphead. Rows should be 12 to 15 inches apart. Sow more seeds every two weeks for a continuous harvest.
Watering and Fertilizing
Water thoroughly at the time of transplanting or seeding. Fertilize with an organic alfalfa meal or another slow-release fertilizer three weeks after transplanting. Keep the soil moist but not overly wet to prevent disease.
Weeding and Mulching
Weed by hand if necessary, being careful not to damage the shallow roots of the lettuce plants. An organic mulch will help conserve moisture, suppress weeds, and keep the soil cool during the warmer months.
Harvesting Lettuce
Harvest lettuce in the morning when it is full-sized but still young and tender. Before maturity, you can harvest leaf lettuce by removing the outer leaves, allowing the center leaves to grow. You can also harvest butterhead, romaine, and loose-leaf types by removing the outer leaves, digging up the whole plant, or cutting the plant about an inch above the soil surface.
