When to plant rosemary in zone 5a — planting calendar

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Showing USDA Zone 5A

Growing SeasonZone 5a

Last frost ~May 10First frost ~Oct 1Today

Start indoorsTransplant / sowHarvestFrost risk

FEBMARAPRMAYJUNJULAUGSEPOCT

Start indoors Mar 1 · Transplant May 10 · First harvest Jul 29 · Wrap by Sep 24

Last spring frostMay 10

Start seeds indoorsMar 1

Transplant outMay 10

First harvestJul 29

Last harvestSep 24

First fall frostOct 1

Why these dates work in zone 5a

Zone 5a's last spring frost averages May 10 and first fall frost Oct 1 — about 144 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 5a?

Rosemary matures in about 80–100 days from transplanting. In zone 5a that means setting plants out around May 10 and first picking around Jul 29.

Will rosemary survive frost in zone 5a?

No — rosemary is frost-sensitive. In zone 5a, wait until after the last frost (around May 10) to plant, and harvest before the first fall frost (around Oct 1).

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