Last spring frostMay 6
Direct sowApr 22
First harvestJul 1
Last harvestAug 12
First fall frostOct 22
Why these dates work in zone 3b
Zone 3b's last spring frost averages May 6 and first fall frost Oct 22 — about 169 frost-free days. Potato tolerates light frost, so you can sow ahead of the last-frost date and keep harvesting into the cooler fall.
Common questions
How long does potato take to grow in zone 3b?
Potato matures in about 70–120 days from sowing. In zone 3b that means sowing around Apr 22 and first picking around Jul 1.
Will potato survive frost in zone 3b?
Yes — potato tolerates light frost. In zone 3b you can sow a little before the last frost (around May 6) and keep harvesting past the first fall frost (around Oct 22).
For soil, spacing, pests and companion planting, see the full potato growing guide →