When to plant rosemary in zone 10b — planting calendar

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Showing USDA Zone 10B

Growing SeasonZone 10b

Last frost ~Jan 15First frost ~Dec 31Today

Start indoorsTransplant / sowHarvestFrost risk

OCTNOVDECJANFEBMARAPRMAYJUNJULAUGSEP

Start indoors Nov 6 · Transplant Jan 15 · First harvest Apr 5 · Wrap by Aug 23

Last spring frostJan 15

Start seeds indoorsNov 6

Transplant outJan 15

First harvestApr 5

Last harvestAug 23

First fall frostDec 31

Why these dates work in zone 10b

Zone 10b's last spring frost averages Jan 15 and first fall frost Dec 31 — about 350 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 10b?

Rosemary matures in about 80–100 days from transplanting. In zone 10b that means setting plants out around Jan 15 and first picking around Apr 5.

Will rosemary survive frost in zone 10b?

No — rosemary is frost-sensitive. In zone 10b, wait until after the last frost (around Jan 15) to plant, and harvest before the first fall frost (around Dec 31).

For soil, spacing, pests and companion planting, see the full rosemary growing guide →