Climate matters. This page is a practical baseline. Confirm cultivar, local frost/heat conditions, mature size and regional restrictions before planting.
Leek — Growing reference
| Scientific name | Allium ampeloprasum var. porrum |
|---|---|
| Seed germination (days) | 7–14 |
| Soil temperature for germination (°C) | 10–23.9 |
| First harvest or flowering (days) | 100–130 |
| Measured from | Transplant |
| Plant spacing (cm) | 15.2–22.9 |
| Mature height (cm) | 45.7–76.2 |
| Mature spread (cm) | 10.2–15.2 |
| USDA hardiness zones | 3–9 |
| Light | Full sun |
| Water | Moderate |
| Sowing method | indoor-start |
Growing directions
Sow seed 1/4 in deep indoors in flats and thin to 2 in; transplant pencil-thick seedlings into 6-in-deep trenches, dropping each plant into a dibber hole and filling with water rather than soil to encourage a long white shank. Gradually fill trenches and hill up soil around stems as they grow to blanch the shanks. Leeks tolerate hard frost and can be left in the ground well into winter for a late harvest. Dig as needed once shanks reach 1 in or more in diameter.
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