Lettuce — Growing reference
| Scientific name | Lactuca sativa |
|---|---|
| Seed germination (days) | 7–10 |
| Soil temperature for germination (°C) | 7.2–18.3 |
| First harvest or flowering (days) | 45–75 |
| Measured from | Seed |
| Plant spacing (cm) | 15.2–30.5 |
| Mature height (cm) | 15.2–30.5 |
| Mature spread (cm) | 15.2–30.5 |
| USDA hardiness zones | 2–11 |
| Light | Partial sun |
| Water | Moderate |
| Sowing method | Direct sow |
Growing directions
Scatter seeds on the surface of moist, well-drained, moderately fertile soil and press lightly without covering — lettuce seeds need light for germination; succession-sow every 2–3 weeks from early spring through fall for a continuous harvest. Thin seedlings to 6–12 inches apart (wider spacing produces larger heads). Lettuce prefers cool temperatures (60–70°F) and bolts quickly in summer heat, becoming bitter and inedible; choose heat-tolerant varieties for summer planting and provide afternoon shade in hot climates. The four main types — crisphead, butterhead, loose-leaf, and romaine — have different maturity times and uses but similar growing requirements. Harvest leaf types by cutting outer leaves; harvest head types when the head feels firm.
Source and local conditions
Typical planning ranges from OpenPlantDB (CC0). Cultivar, climate, season and growing method can change these values. Confirm the seed label and local guidance before planting.
Source & verification
OpenPlantDB · CC0