Bok Choy in Zone 4a & 4b
Brassica rapa subsp. chinensis
When to plant bok choy in zone 4b
Zones 4a and 4b share the same average frost dates in our data, so this page covers both.
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Bok Choy tolerates either.
| Start indoors | Apr 10–Apr 17 |
|---|---|
| Direct sow / transplant outside | May 15–May 22 |
| Estimated harvest | Jul 4–Jul 11 (~50 days after planting) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 1 ft.
Bok choy is one of the fastest vegetables you can put in the ground, ready in under two months, and its crunchy white stalks and tender leaves work in everything from stir-fries to soups. It's also one of the quickest to ruin if you plant it at the wrong time of year.
How bok choy fits zone 4's season
Zone 4b's frost-free window runs about 128 days, from May 15 to September 20. Bok Choy needs about 50 days from sowing to first harvest.
Good companions
Where to buy bok choy seeds
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing bok choy" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 4b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →
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Growing Bok Choy in USDA zone 4b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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