When to plant cucumber in zone 4b — planting calendar

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Showing USDA Zone 4B

Growing SeasonZone 4b

Last frost ~May 15First frost ~Sep 25Today

Start indoorsTransplant / sowHarvestFrost risk

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Start indoors Apr 24 · Sow May 29 · First harvest Jul 18 · Wrap by Sep 12

Last spring frostMay 15

Start seeds indoorsApr 24

Direct sowMay 29

First harvestJul 18

Last harvestSep 12

First fall frostSep 25

Why these dates work in zone 4b

Zone 4b's last spring frost averages May 15 and first fall frost Sep 25 — about 133 frost-free days. Cucumber is frost-sensitive, so the 2w after 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 3 weeks ahead gives strong transplants ready the moment the soil warms.

Common questions

How long does cucumber take to grow in zone 4b?

Cucumber matures in about 50–70 days from sowing. In zone 4b that means sowing around May 29 and first picking around Jul 18.

Will cucumber survive frost in zone 4b?

No — cucumber is frost-sensitive. In zone 4b, wait until after the last frost (around May 15) to plant, and harvest before the first fall frost (around Sep 25).

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