Lettuce
Lactuca sativa
📖 About this plant
The most popular salad green worldwide, lettuce is a fast-growing, cool-season annual available in four main types: crisphead (iceberg), butterhead (Bibb), romaine (cos), and looseleaf. Rich in vitamins A and K, lettuce is low in calories and high in water content. It grows quickly (30-60 days from seed) and is perfect for succession planting. Best grown in spring and fall as heat causes bolting and bitterness.
🧑🌾 Care requirements
Full sun to partial shade (4-6 hrs)
Every 1-2 days
Moderate (50-70%)
10-21°C
Moisture-retentive, well-draining loam rich in organic matter; pH 6.0-7.0. Consistent moisture prevents bolting and bitterness
Nitrogen-rich fertilizer (high-N liquid feed) every 2 weeks; side-dress with compost or balanced fertilizer 2-3 weeks after transplanting; consistent feeding promotes tender, rapid leaf growth
🌐 Common Names
📋 Plant facts
- 🌍 Origin
- Mediterranean region, Near East
- 📏 Max height
- 15-30 cm (leaf types); up to 45 cm for romaine and butterhead
- 📐 Spread
- 15-30 cm
- 🕰️ Bloom time
- Summer
- 🎨 Bloom color
- Yellow
- 🍃 Foliage color
- Green
- ⏳ Lifespan
- Annual
- 📈 Growth rate
- Fast
- ☠️ Toxicity
- Non-toxic; all parts edible. Lactucarium (lettuce opium) in wild lettuce has mild sedative properties but cultivated lettuce contains negligible amounts
- 🌱 Propagation
- Direct sow seeds 0.3 cm deep; succession sow every 2 weeks for continuous harvest; ideal soil temperature for germination is 13-18°C; start indoors 4-6 weeks before last frost for early crop
🛡️ Health & Safety
Non-toxic; all parts edible. Lactucarium (lettuce opium) in wild lettuce has mild sedative properties but cultivated lettuce contains negligible amounts
Common issues
- Bolting (going to seed) in hot weather — lettuce becomes bitter
- Slugs and snails chewing leaves
- Tip burn from calcium deficiency or inconsistent watering
- Downy mildew in cool humid conditions
💡 Care tips
- Plant in succession every 2 weeks for continuous harvest
- Bolts and turns bitter in hot weather above 24°C
- HARVEST outer leaves first for cut-and-come-again
- Shade in afternoon to extend growing season
