Zone 6b covers 17 days of last-frost dates. We measured Springfield, MO at Apr 6 and Detroit, MI at Apr 23. 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 6b
Zone 6b's last spring frost averages Apr 19 and first fall frost Nov 6 — about 201 frost-free days. Mustard Greens tolerates light frost, so you can sow ahead of the last-frost date and keep harvesting into the cooler fall. There's also room for a fall succession sowing around Sep 25 for a second harvest before frost.
Common questions
How long does mustard greens take to grow in zone 6b?
Mustard Greens matures in about 25–40 days from sowing. In zone 6b that means sowing around Mar 22 and first picking around Apr 16.
Will mustard greens survive frost in zone 6b?
Yes — mustard greens tolerates light frost. In zone 6b you can sow a little before the last frost (around Apr 19) and keep harvesting past the first fall frost (around Nov 6).
Can I plant a second crop of mustard greens in zone 6b?
Yes — in zone 6b there's time for a fall sowing around Sep 25 for a second harvest before frost.
For soil, spacing, pests and companion planting, see the full mustard greens growing guide →