Complete Guide to Lettuce Farming (Lactuca sativa)

Scientific Name: Lactuca sativa
Popular Varieties: Bibb, Black Seeded Simpson, Buttercrunch, Butterhead, Cos, Crisphead, Green Leaf, Iceberg, Looseleaf, Mesclun Greens, Oakleaf, Parris Island, Red Leaf, Red Salad Bowl, and Romaine.

With such a wide range of colors, textures, and flavors, lettuce is one of the most rewarding and diverse crops to grow. Whether you prefer crisp iceberg or tender butterhead, your salads will never taste the same again.

🥬 Understanding Lettuce Growth Conditions

Lettuce thrives in cool weather, ideally between 10°C and 18°C. It’s a cool-season crop that performs best during the early spring and fall months.

While lettuce is adaptable to many conditions, extreme heat causes plants to bolt (go to seed) or leaves to wilt and turn bitter. For best results, provide full sun in cool climates and partial shade in warmer areas.

Soil Requirements

• pH: 6.2 to 6.8 (minimum 6.0 if liming)

• Soil Type: Well-drained, loose, and rich in organic matter

• Moisture: Keep consistently moist but not waterlogged

Before planting, amend the soil with compost or aged manure to promote tender, flavorful leaves.

🌾 Planting Lettuce

Lettuce can be direct-seeded into the garden or transplanted from seedlings. Here’s how:

🌱 Direct Seeding

• Depth: 1/8 inch deep

• Spacing: 1 inch apart in rows 12–18 inches apart

• Thinning: Once plants have 2–3 true leaves, thin to:

  • 12 inches apart for Crisphead varieties

  • 6–10 inches for Looseleaf, Romaine, or Butterhead types

Alternatively, you can broadcast seeds for looseleaf types instead of planting in rows.

🌿 Transplanting

• Start seeds indoors 3–4 weeks before transplanting.

• Harden off seedlings by reducing water and temperature for 3 days before planting out.

• Spacing:

  • Crisphead: 12 inches apart in rows 18 inches apart

  • Other types: 6–10 inches apart in rows 12–18 inches apart

Use row covers to:

• Protect early plantings from frost

• Shield young plants from pests

• Provide shade during warm spells

👉 Tip: For a continuous harvest, plant new seeds every 1–2 weeks and mix varieties with different maturity dates.

💧 Watering and Maintenance

Lettuce has shallow roots, so it needs consistent moisture to stay tender. Drought stress and high temperatures—especially at night—encourage bolting.

Key Tips:

• Mulch to retain moisture and suppress weeds (avoid if slugs are an issue).

• Fertilize lightly with fish emulsion or compost tea. Avoid high-nitrogen fertilizers that can make leaves bitter.

• Water gently but frequently to keep soil evenly moist.

If growing in warm regions, position lettuce where it gets partial shade—for example, under taller crops or a shade net.

🧺 Harvesting Lettuce

Lettuce can be harvested at various growth stages, depending on your needs:

Type	Harvest Time	Notes
Microgreens	2 weeks after germination	Cut at 3–4 inches tall
Baby Greens	28–35 days	Ideal for looseleaf, butterhead, and romaine
Mature Leaves	50–70 days	Harvest before bolting for best taste
Head Lettuce (Iceberg/Romaine)	60–80 days	Harvest before outer leaves brown

Harvesting Tips:

• Pick early in the morning before the sun is high to prevent wilting.

• Cut leaves 1 inch above the ground to allow regrowth for multiple harvests.

• For whole heads, cut the plant at the base before seed stalks appear.

If the plant starts forming a central stalk, it’s preparing to bolt, and leaves may become bitter.

🥶 Storing Lettuce

After harvesting:

1. Wash thoroughly to remove soil or chemicals.

2. Rinse and dry using a colander or salad spinner.

3. Store in a plastic bag or wrapped in paper towels inside the refrigerator.

✅ Ideal Storage Conditions:

• Temperature: 32°C (0°C actual optimal)

• Humidity: 96%

Avoid storing lettuce with apples, pears, or bananas, as they emit ethylene gas that causes browning and spoilage.

🌾 Seed Saving and Cleaning

To save seeds:

1. Allow plants to flower and dry.

2. Shake dried seed heads in a bag to collect seeds.

3. Rub between hands to separate chaff.

4. Use a fine mesh sieve to remove debris.

Winnowing can be tricky since lettuce seeds and chaff are similar in weight. Use reverse screening for better cleaning.

⚠️ Safety Note: The fine dust from seed cleaning can irritate eyes and lungs. Always wear a mask and goggles or work outdoors.

🌿 Final Thoughts

Lettuce (Lactuca sativa) is one of the easiest and most rewarding crops to grow, offering fresh greens from early spring through late fall. With the right soil, steady moisture, and proper variety selection, you can enjoy a steady supply of crisp, healthy lettuce all season long.

Whether you’re a backyard gardener or planning small-scale commercial farming, this guide gives you everything you need to grow lettuce successfully—from seed to harvest and beyond.