Plant Pumpkins in Zone 4b
Seed-starting, transplant & harvest dates for USDA Zone 4b
Zone 4b averages 146 frost-free days, running from a last spring frost around May 5 to a first fall frost around September 28. Pumpkins needs roughly 100 days from planting out to first harvest, so it uses about 68 percent of that window. Pumpkins is a tender crop, which is what decides where in the window it belongs.
Because pumpkins needs a head start, sow seed indoors around Apr 14, about 3 weeks ahead of the Zone 4b last frost. Transplants go out around May 19. Starting earlier than that in Zone 4b usually backfires: plants outgrow their cells and stall when they finally hit cold soil.
Fall planting: pumpkins in Zone 4b
Pumpkins has no useful fall window in Zone 4b. Pumpkins are already a fall harvest, but they are planted in early summer. There is no second sowing.
Pumpkins are already a fall harvest, but they are planted in early summer. There is no second sowing.
Fall dates are counted backward from the Zone 4b average first frost, not forward from a sowing date. See the fall planting calendar by zone for the full method.
Spring vs fall pumpkins in Zone 4b
| Planting | Sow or start | In the ground | Harvest |
|---|---|---|---|
| Spring | Apr 14 | May 19 | Aug 27 |
| Fall | — | — | — |
Pumpkins in nearby zones
Further reading on pumpkins
- When to start seeds indoors by zone
Indoor start dates for pumpkins, counted back from your last frost.
- Hardening off seedlings: a schedule
A day by day plan for moving pumpkins seedlings outdoors.
- Best grow lights for seed starting
What light seedlings actually need, and which fixtures deliver it.
Other crops in Zone 4b
Frequently asked questions
When should I start pumpkins in Zone 4b?
Start pumpkins seeds indoors around Apr 14 (Zone 4b).
Can I direct sow pumpkins in Zone 4b?
Yes, direct sow around May 19.
Can I plant pumpkins in the fall in Zone 4b?
Pumpkins has no useful fall window in Zone 4b. Pumpkins are already a fall harvest, but they are planted in early summer. There is no second sowing.
Will pumpkins survive frost in Zone 4b?
No. Pumpkins is a tender crop and a single light frost ends it, so every Zone 4b planting has to finish before the average first frost.