🌿 Lettuce

Lettuce should be grown in fertile, well-drained soil that retains moisture without becoming soggy. Loose soil enriched with plenty of well-decomposed compost or organic matter is ideal; avoid compacted or crusted soils. Maintain regular humidity with good aeration (raised beds are useful in heavy clay). The best pH is slightly acidic to neutral (around 6.0-7.0); avoid saline soils and fresh manures, which can burn roots.

Sow lettuce (Lactuca sativa) in cool conditions for optimum germination and quality. Sow directly in the ground as soon as the soil can be worked in spring, then in late summer for autumn crops; in mild climates, sow in autumn for overwintering. For continuous harvesting, sow small seedlings every 1-2 weeks. Sowing depth: sow very shallowly (approx. 3-6 mm) and cover lightly or press into the soil; seeds need constant moisture and benefit from light, but must not dry out. Seeds need constant humidity and benefit from light, but must not dry out. Typical germination takes 7-14 days in cool conditions. Temperature: lettuce germinates best in cool soil (around 10-18°C / 50-65°F). High temperatures can reduce or prevent germination; in hot weather, sow in the evening, provide light shade and keep the soil cool and moist (or start seeds indoors in a cooler place). Spacing/thinning: thin seedlings to final spacing according to lettuce type - leaf lettuce about 15-25 cm (6-10 in) apart; romaine/cos and butterhead about 20-30 cm (8-12 in); ear types generally 25-35 cm (10-14 in). Rows are generally 30-45 cm apart. Transplanting (optional): start seeds indoors 3-4 weeks before transplanting. Transplant when seedlings have several true leaves and are robust; harden off first. Place seedlings at the same depth as they grew in the tray; firm the soil and water well. Location: use fertile, well-drained, regularly moist soil. During hot periods, provide afternoon shade and adequate watering to reduce bitterness and bolting.

Lettuce is a fast-growing, shallow-rooted crop that responds best to a regular, moderate supply of nitrogen and sufficient potassium. - Basic fertilization: Before planting, incorporate well-prepared compost and, if necessary according to soil analysis, a balanced plant fertilizer (e.g. 5-5-5 or 10-10-10). Avoid over-fertilizing at planting time. - Nitrogen management: Apply a light side-dressing of nitrogen fertilizer when plants are established (about 2-3 weeks after transplanting or once seedlings have several true leaves). For long-season varieties (romaine lettuce, head lettuce), repeat a light side-dressing 2 to 3 weeks later; for leaf lettuce, a single side-dressing is often sufficient. - Method: Place fertilizer in strips a few centimetres from the row or base of the plant and water immediately; avoid getting fertilizer on the leaves. - Containers: use a controlled-release fertilizer mixed with the potting medium at the label dose, or fertilize weekly or fortnightly with a dilute, balanced soluble fertilizer. - Precautions: Excess nitrogen can promote sluggish growth, increase nitrate build-up and contribute to tip burn; maintain even humidity and avoid late, heavy nitrogen applications as harvest approaches.

Apply a light organic mulch (clean straw, leaf mold, compost or untreated grass clippings) after seedling establishment to conserve moisture, reduce soil splash and keep the soil cooler for better-quality leaves. Mulch should be 2 to 5 cm thick and removed to within a few centimetres of the stem or crown to prevent rotting. In hot weather, mulch helps prevent bolting by moderating soil temperature; in cool weather, use only a thin layer to allow the soil to warm up. Watch out for slugs and snails, which can take shelter under the mulch, and avoid fresh mulches with high nitrogen content, which can heat up as they decompose.