Mustard Greens in Zone 5a & 5b
Brassica juncea
When to plant mustard greens in zone 5b
Zones 5a and 5b share the same average frost dates in our data, so this page covers both.
Method: Direct sow: Direct-sow outside. Mustard Greens doesn't transplant well, or doesn't need the extra time indoors.
| Start indoors | Not typically started indoors |
|---|---|
| Direct sow / transplant outside | Apr 19–Apr 26 |
| Estimated harvest | May 29–Jun 5 (~40 days after direct-sowing) |
Spacing: 4 per square foot (square-foot-gardening spacing). Mature height: 1-2 ft.

Mustard greens are one of the fastest crops you can grow for a full harvest, direct-sown and ready to cut in under six weeks, with a peppery bite that gets sharper the longer a leaf sits on the plant. They're also one of the most cold-tolerant greens, holding up to frost that would finish off lettuce.
How mustard greens fits zone 5's season
Zone 5b's frost-free window runs about 148 days, from May 10 to October 5. Mustard Greens needs about 40 days from sowing to first harvest.
Good companions
- Lettuce: Similar light/water needs for a shared salad bed.
- Carrot: Non-competing pairing with mutual pest benefit.
Where to buy mustard greens seeds
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing mustard greens" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 5b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →

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Growing Mustard Greens in USDA zone 5b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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