When to plant corn 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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Sow May 29 · First harvest Aug 7 · Wrap by Aug 28

Last spring frostMay 15

Direct sowMay 29

First harvestAug 7

Last harvestAug 28

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. Corn 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.

Common questions

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

Corn matures in about 70–90 days from sowing. In zone 5b that means sowing around May 29 and first picking around Aug 7.

Will corn survive frost in zone 5b?

No — corn is frost-sensitive. In zone 5b, wait until after the last frost (around May 15) to plant, and harvest before the first fall frost (around Sep 30).

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