Zone 7b covers 44 days of last-frost dates. We measured Oklahoma City, OK at Mar 12 and Reno, NV at Apr 25. 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 7b
Zone 7b's last spring frost averages Apr 4 and first fall frost Nov 12 — about 222 frost-free days. Rosemary is frost-sensitive, so the around last frost timing builds in a safety margin against a late cold snap — setting plants out too early risks losing them to frost. Starting seeds indoors 10 weeks ahead gives strong transplants ready the moment the soil warms.
Common questions
How long does rosemary take to grow in zone 7b?
Rosemary matures in about 80–100 days from transplanting. In zone 7b that means setting plants out around Apr 4 and first picking around Jun 23.
Will rosemary survive frost in zone 7b?
No — rosemary is frost-sensitive. In zone 7b, wait until after the last frost (around Apr 4) to plant, and harvest before the first fall frost (around Nov 12).
For soil, spacing, pests and companion planting, see the full rosemary growing guide →