When to plant rosemary in zone 10a — planting calendar

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Showing USDA Zone 10A

Growing SeasonZone 10a

Last frost ~Jan 31First frost ~Dec 15Today

Start indoorsTransplant / sowHarvestFrost risk

NOVDECJANFEBMARAPRMAYJUNJULAUGSEP

Start indoors Nov 22 · Transplant Jan 31 · First harvest Apr 21 · Wrap by Sep 8

Last spring frostJan 31

Start seeds indoorsNov 22

Transplant outJan 31

First harvestApr 21

Last harvestSep 8

First fall frostDec 15

Why these dates work in zone 10a

Zone 10a's last spring frost averages Jan 31 and first fall frost Dec 15 — about 318 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 10a?

Rosemary matures in about 80–100 days from transplanting. In zone 10a that means setting plants out around Jan 31 and first picking around Apr 21.

Will rosemary survive frost in zone 10a?

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

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