Zone 9b covers 17 days of last-frost dates. We measured Las Vegas, NV at Feb 6 and Sacramento, CA at Feb 23. 10 of the 15 places we checked in this zone don't dependably freeze at all. 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 9b
Zone 9b's last spring frost averages Feb 9 and first fall frost Dec 8 — about 302 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 9b?
Rhubarb matures in about 548–730 days from transplanting. In zone 9b that means setting plants out around Jan 26 and first picking around Jul 28.
Will rhubarb survive frost in zone 9b?
Yes — rhubarb tolerates light frost. In zone 9b you can set plants out a little before the last frost (around Feb 9) and keep harvesting past the first fall frost (around Dec 8).
For soil, spacing, pests and companion planting, see the full rhubarb growing guide →