When to plant leek in zone 5b — planting calendar

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Showing USDA Zone 5B

Growing SeasonZone 5b

Last frost ~May 15First frost ~Sep 30Today

Start indoorsTransplant / sowHarvestFrost risk

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Start indoors Feb 20 · Transplant May 1 · First harvest Aug 9 · Wrap by Sep 30

Last spring frostMay 15

Start seeds indoorsFeb 20

Transplant outMay 1

First harvestAug 9

Last harvestSep 30

First fall frostSep 30

Why these dates work in zone 5b

Zone 5b's last spring frost averages May 15 and first fall frost Sep 30 — about 138 frost-free days. Leek 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 12 weeks ahead gives strong transplants ready the moment the soil warms.

Common questions

How long does leek take to grow in zone 5b?

Leek matures in about 100–120 days from transplanting. In zone 5b that means setting plants out around May 1 and first picking around Aug 9.

Will leek survive frost in zone 5b?

Yes — leek tolerates light frost. In zone 5b you can set plants out a little before the last frost (around May 15) and keep harvesting past the first fall frost (around Sep 30).

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