Zone 4b covers 52 days of last-frost dates. We measured Pierre, SD at Apr 28 and Jackson, WY at Jun 19. Give us your town or ZIP and we'll use ten years of daily lows recorded at your own coordinates instead of the middle of that range.
Why these dates work in zone 4b
Zone 4b's last spring frost averages May 4 and first fall frost Oct 20 — about 169 frost-free days. Blueberry tolerates light frost, so you can set plants out ahead of the last-frost date and keep harvesting into the cooler fall.
Common questions
How long does blueberry take to grow in zone 4b?
Blueberry matures in about 365–730 days from transplanting. In zone 4b that means setting plants out around Apr 20 and first picking around Apr 20.
Will blueberry survive frost in zone 4b?
Yes — blueberry tolerates light frost. In zone 4b you can set plants out a little before the last frost (around May 4) and keep harvesting past the first fall frost (around Oct 20).
For soil, spacing, pests and companion planting, see the full blueberry growing guide →