Zone 6a covers 28 days of last-frost dates. We measured Omaha, NE at Apr 14 and Flagstaff, AZ at May 12. 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 6a
Zone 6a's last spring frost averages Apr 22 and first fall frost Nov 1 — about 193 frost-free days. Rhubarb 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 rhubarb take to grow in zone 6a?
Rhubarb matures in about 548–730 days from transplanting. In zone 6a that means setting plants out around Apr 8 and first picking around Oct 8.
Will rhubarb survive frost in zone 6a?
Yes — rhubarb tolerates light frost. In zone 6a you can set plants out a little before the last frost (around Apr 22) and keep harvesting past the first fall frost (around Nov 1).
For soil, spacing, pests and companion planting, see the full rhubarb growing guide →