Zone 7b covers 44 days of last-frost dates. We measured Oklahoma City, OK at Mar 12 and Reno, NV at Apr 25. Give us your town or ZIP and we'll use ten years of daily lows recorded at your own coordinates instead of the middle of that range.
Why these dates work in zone 7b
Zone 7b's last spring frost averages Apr 4 and first fall frost Nov 12 — about 222 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 Sep 3 for a second harvest before frost.
Common questions
How long does swiss chard take to grow in zone 7b?
Swiss Chard matures in about 50–60 days from sowing. In zone 7b that means sowing around Mar 21 and first picking around May 10.
Will swiss chard survive frost in zone 7b?
Yes — swiss chard tolerates light frost. In zone 7b you can sow a little before the last frost (around Apr 4) and keep harvesting past the first fall frost (around Nov 12).
Can I plant a second crop of swiss chard in zone 7b?
Yes — in zone 7b there's time for a fall sowing around Sep 3 for a second harvest before frost.
For soil, spacing, pests and companion planting, see the full swiss chard growing guide →