Pumpkin in Zone 3a & 3b
Cucurbita pepo
Pumpkin can grow in zones 3a and 3b, but its usual harvest starts after the average first frost, so it takes an early variety and frost protection. Plant it outside Jun 6–Jun 13.
When to plant pumpkin in zone 3b
Zones 3a and 3b share the same average frost dates, so this page covers both.
Method: Direct sow: Direct-sow outside. It doesn't transplant well, or doesn't need the extra time indoors.
| Start indoors | Not typically started indoors |
|---|---|
| Direct sow / transplant outside | Jun 6–Jun 13 |
| Estimated harvest | Sep 24–Oct 1 (~110 days after direct-sowing) |
Spacing: about 10 square feet per plant (square-foot-gardening spacing). Mature height: 1-1.5 ft.
Before you plant: Zone 3b's first fall frost usually comes close to or before the harvest. See the details below.
Plant alongside it in zone 3b
These go outside within two weeks of pumpkin in zone 3b, so one planting day can cover them.
- TomatoJun 13–Jun 20
- Bush BeansJun 6–Jun 13
- CucumberJun 6–Jun 13
- ZucchiniJun 6–Jun 13
- Winter SquashJun 6–Jun 13
- BroccoliniMay 30–Jun 6
Pumpkins ask for more room and more patience than almost anything else in the garden: around 110 days from seed to harvest, and vines that sprawl far enough that planning calls for a mere tenth of a plant per square foot, in practice, that means giving one plant several square feet to itself.
How pumpkin fits zone 3's season
Zone 3b's frost-free window runs about 98 days, from May 30 to September 5. Pumpkin needs about 110 days from sowing to first harvest.
Frost risk in zone 3b: Harvest usually starts about 19 days after zone 3b's average first frost (September 5), and pumpkin is damaged by even a light frost. Expect frost to arrive first in most years unless you choose the fastest-maturing variety you can find, start it as early as the dates above allow, and cover plants on cold nights. (Frost tolerance and protection advice: Purdue Extension.)
Pumpkin planting windows in every zone
Zone 3b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Harvest |
|---|---|---|---|
| 3a & 3b (your zone) | Not usually | Jun 6–Jun 13 | Sep 24–Oct 1 |
| 4a & 4b | Not usually | May 22–May 29 | Sep 9–Sep 16 |
| 5a & 5b | Not usually | May 17–May 24 | Sep 4–Sep 11 |
| 6a & 6b | Not usually | May 2–May 9 | Aug 20–Aug 27 |
| 7a & 7b | Not usually | Apr 17–Apr 24 | Aug 5–Aug 12 |
| 8a & 8b | Not usually | Apr 1–Apr 8 | Jul 20–Jul 27 |
| 9a & 9b | Not usually | Feb 22–Mar 1 | Jun 12–Jun 19 |
| 10a & 10bSpring window | Feb | Mar | ~110 days after transplanting |
| Summer window | Jun–Jul | Jul–Aug | ~110 days after transplanting |
Harvest dates are about 110 days after the sow or plant-out date.
Good companions
- Sweet Corn: The same 'three sisters' mechanism as winter squash: WSU Extension confirms pumpkin's broad leaves shade the soil, suppressing weeds and reducing evaporation around corn.
Where to buy pumpkin seeds
Botanical Interests · True Leaf Market · Burpee · High Mowing Organic Seeds (each supplier's pumpkin seeds)
Varieties we recommend, and where to get them:
- Racer (F1): Bred by Johnny's with the University of New Hampshire specifically for earliness, at 85 days against the usual 110, on short vigorous vines. Buy: High Mowing Organic Seeds Full notes
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing pumpkin" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 3b calendar · Plan your beds in the Garden Designer →
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Growing Pumpkin in USDA zone 3b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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