When to plant swiss chard in zone 3b — planting calendar

Growing SeasonZone 3b

Last frost ~May 6First frost ~Oct 22Today

Start indoorsTransplant / sowHarvestFrost risk

MARAPRMAYJUNJULAUGSEPOCT

Start indoors Apr 8 · Sow Apr 22 · First harvest Jun 11 · Wrap by Oct 1

Last spring frostMay 6

Start seeds indoorsApr 8

Direct sowApr 22

First harvestJun 11

Last harvestOct 1

Fall succession sowAug 13

First fall frostOct 22

Why these dates work in zone 3b

Zone 3b's last spring frost averages May 6 and first fall frost Oct 22 — about 169 frost-free days. Swiss Chard tolerates light frost, so you can sow ahead of the last-frost date and keep harvesting into the cooler fall. Starting seeds indoors 4 weeks ahead gives strong transplants ready the moment the soil warms. There's also room for a fall succession sowing around Aug 13 for a second harvest before frost.

Common questions

How long does swiss chard take to grow in zone 3b?

Swiss Chard matures in about 50–60 days from sowing. In zone 3b that means sowing around Apr 22 and first picking around Jun 11.

Will swiss chard survive frost in zone 3b?

Yes — swiss chard tolerates light frost. In zone 3b you can sow a little before the last frost (around May 6) and keep harvesting past the first fall frost (around Oct 22).

Can I plant a second crop of swiss chard in zone 3b?

Yes — in zone 3b there's time for a fall sowing around Aug 13 for a second harvest before frost.

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

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