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. Lemon Balm tolerates light frost, so you can set plants out ahead of the last-frost date and keep harvesting into the cooler fall. Starting seeds indoors 6 weeks ahead gives strong transplants ready the moment the soil warms.
Common questions
How long does lemon balm take to grow in zone 9b?
Lemon Balm matures in about 60–90 days from transplanting. In zone 9b that means setting plants out around Feb 9 and first picking around Apr 10.
Will lemon balm survive frost in zone 9b?
Yes — lemon balm 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 lemon balm growing guide →