Lettuce in Zone 4a & 4b
Lactuca sativa
Yes, lettuce grows in zones 4a and 4b. Start seeds indoors Apr 17–Apr 24 and plant out May 1–May 8. For a fall crop, plant out Jul 23–Aug 6.
When to plant lettuce in zone 4b
Zones 4a and 4b share the same average frost dates, so this page covers both.
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Either works.
| Window | Spring window |
|---|---|
| Start indoors | Apr 17–Apr 24 |
| Direct sow / transplant outside | May 1–May 8 |
| Estimated harvest | Jun 15–Jun 22 (~45 days after planting) |
| Window | Fall window |
|---|---|
| Start indoors | Not typically started indoors |
| Direct sow / transplant outside | Jul 23–Aug 6 |
| Estimated harvest | Sep 6–Sep 20 (~45 days after planting) |
Spacing: 4 per square foot (square-foot-gardening spacing). Mature height: 0.5-1 ft.
Fall window: the last sowing date is the average first frost minus days to maturity, the method in Purdue Extension's fall garden guide, which lists lettuce for late-summer planting.
Plant alongside it in zone 4b
These go outside within two weeks of lettuce in zone 4b, so one planting day can cover them.
- OnionApr 24–May 1
- CabbageMay 1–May 8
- BroccoliMay 1–May 8
- Flower SproutsMay 1–May 8
- Gai Lan (Chinese Broccoli)May 1–May 8
- KalettesMay 1–May 8
If you want a first-garden success story in under six weeks, lettuce is it. It germinates reliably, tolerates a light frost, and, unlike a lot of vegetables. You can harvest outer leaves gradually instead of waiting for one big harvest day.
How lettuce fits zone 4's season
Zone 4b's frost-free window runs about 128 days, from May 15 to September 20. Lettuce needs about 45 days from sowing to first harvest.
Lettuce planting windows in every zone
Zone 4b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Harvest |
|---|---|---|---|
| 2a & 2bSpring window | Apr 22–Apr 29 | May 6–May 13 | Jun 20–Jun 27 |
| Fall window | Not usually | Jul 4–Jul 18 | Aug 18–Sep 1 |
| 3a & 3bSpring window | May 2–May 9 | May 16–May 23 | Jun 30–Jul 7 |
| Fall window | Not usually | Jul 8–Jul 22 | Aug 22–Sep 5 |
| 4a & 4bSpring window (your zone) | Apr 17–Apr 24 | May 1–May 8 | Jun 15–Jun 22 |
| Fall window | Not usually | Jul 23–Aug 6 | Sep 6–Sep 20 |
| 5a & 5bSpring window | Apr 12–Apr 19 | Apr 26–May 3 | Jun 10–Jun 17 |
| Fall window | Not usually | Aug 7–Aug 21 | Sep 21–Oct 5 |
| 6a & 6bSpring window | Mar 28–Apr 4 | Apr 11–Apr 18 | May 26–Jun 2 |
| Fall window | Not usually | Aug 17–Aug 31 | Oct 1–Oct 15 |
| 7a & 7bSpring window | Mar 13–Mar 20 | Mar 27–Apr 3 | May 11–May 18 |
| Fall window | Not usually | Aug 27–Sep 10 | Oct 11–Oct 25 |
| 8a & 8bSpring window | Feb 25–Mar 4 | Mar 11–Mar 18 | Apr 25–May 2 |
| Fall window | Not usually | Sep 12–Sep 26 | Oct 27–Nov 10 |
| 9a & 9bSpring window | Jan 18–Jan 25 | Feb 1–Feb 8 | Mar 18–Mar 25 |
| Fall window | Not usually | Oct 7–Oct 21 | Nov 21–Dec 5 |
| 10a & 10bFall window | Aug–Dec | Sep–Jan | ~45 days after transplanting |
Harvest dates are about 45 days after the sow or plant-out date, not after starting seeds indoors.
Zone 2 sows before zone 3 here, which looks wrong and is not. USDA zones rank winter cold, not season length, and zone 2 is mostly interior Alaska, where hard winters come with warm summers. More on what a zone measures.
Good companions
- Carrot: Shallow lettuce roots don't compete with deep carrot roots.
- Radish: Radish matures fast and breaks up soil for lettuce.
Where to buy lettuce seeds
Botanical Interests · True Leaf Market · Burpee · High Mowing Organic Seeds (each supplier's lettuce seeds)
Varieties we recommend, and where to get them:
- Summertime (crisphead): Seed Savers Exchange notes it tolerates heat and resists bolting, another hot-climate option. Buy: True Leaf Market Full notes
- Winter Density (Bibb-Romaine): Seed Savers Exchange describes this as slow to bolt in summer heat while also cold tolerant, a rare combination that spans both ends of lettuce's growing season instead of covering just the hot-weather half like Slobolt and Summertime. Buy: True Leaf Market · High Mowing Organic Seeds Full notes
- Buttercrunch (best for classic butterhead): Johnny's grows this Cornell-bred 1963 AAS winner into a small, tightly bunched 6-inch rosette with crisp, sweet leaves and compact hearts that blanch yellow inside. Buy: Botanical Interests · True Leaf Market · Burpee Full notes
- Black Seeded Simpson (best for fast, easy leaf lettuce): On Cornell Cooperative Extension's selected list of vegetable varieties for New York gardeners as a looseleaf lettuce, and starred there as a gardener favorite: at least four New York gardeners rated it, averaging above 3.5 stars. Buy: Botanical Interests · True Leaf Market · Burpee Full notes
- Little Gem (best for compact spaces, containers): Johnny's describes this French heirloom as a mini romaine-butterhead cross, about 40 days, heavily savoyed leaves with a buttery texture, quick to close and blanch its internal leaves. Buy: Botanical Interests · True Leaf Market · Burpee Full notes
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing lettuce" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
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Growing Lettuce in USDA zone 4b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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