Leek in Zone 4a & 4b
Allium ampeloprasum
When to plant leek in zone 4b
Zones 4a and 4b share the same average frost dates in our data, so this page covers both.
Method: Start indoors: Start indoors from seed, then transplant outside. Leek needs a head start most zones can't give it by direct-sowing alone.
| Start indoors | Mar 6–Mar 13 |
|---|---|
| Direct sow / transplant outside | Apr 24–May 1 |
| Estimated harvest | Aug 12–Aug 19 (~110 days after transplanting) |
Spacing: 9 per square foot (square-foot-gardening spacing). Mature height: 1-2 ft.
Leeks take their time, 110 days from seed to harvest, but they ask for very little in return once they're in the ground. If you've grown onions or garlic, leeks are the same family playing a longer, more patient game.
How leek fits zone 4's season
Zone 4b's frost-free window runs about 128 days, from May 15 to September 20. Leek needs about 110 days from transplant to first harvest.
Good companions
- Carrot: Same allium/carrot pest-masking effect measured for onion and carrot (Uvah & Coaker 1984) — a real, peer-reviewed field study, not folklore.
Where to buy leek seeds
See why we recommend these suppliers →
As an Amazon Associate we earn from qualifying purchases. Some links on this page also go to other retailers we may earn a commission from as an affiliate, at no extra cost to you. We only recommend products with a genuine consensus of positive, independent reviews. See the sources cited on each item.
See it growing
Search YouTube for "growing leek" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 4b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →
Pin this for later
Growing Leek in USDA zone 4b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
Save to Pinterest