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. 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 Jul 22 for a second harvest before frost.
Common questions
How long does swiss chard take to grow in zone 5b?
Swiss Chard matures in about 50–60 days from sowing. In zone 5b that means sowing around May 1 and first picking around Jun 20.
Will swiss chard survive frost in zone 5b?
Yes — swiss chard tolerates light frost. In zone 5b you can sow a little before the last frost (around May 15) and keep harvesting past the first fall frost (around Sep 30).
Can I plant a second crop of swiss chard in zone 5b?
Yes — in zone 5b there's time for a fall sowing around Jul 22 for a second harvest before frost.
For soil, spacing, pests and companion planting, see the full swiss chard growing guide →
