Climate matters. This page is a practical baseline. Confirm cultivar, local frost/heat conditions, mature size and regional restrictions before planting.
Iceberg Lettuce — Growing reference
| Scientific name | Lactuca sativa |
|---|---|
| Seed germination (days) | 7–14 |
| Soil temperature for germination (°C) | 4.4–21.1 |
| First harvest or flowering (days) | 70–85 |
| Measured from | Seed |
| Plant spacing (cm) | 25.4–35.6 |
| Mature height (cm) | 20.3–30.5 |
| Mature spread (cm) | 25.4–35.6 |
| USDA hardiness zones | 3–9 |
| Light | Full sun |
| Water | Moderate |
| Sowing method | Direct sow |
Growing directions
This heirloom crisphead forms compact, tight heads about eight inches across with firm, mild, refreshingly crunchy leaves. Sow in cool weather, either early spring or late summer, since heat triggers bolting and bitterness. Thin plants to give each head room to fill out and keep the soil consistently moist. Harvest when heads feel firm and full, cutting at the base in the cool part of the day.
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.
OpenPlantDB · iceberg-head-lettuce-sgs
Source & verification
OpenPlantDB · CC0