bok choy (Brassica rapa subsp. chinensis), photographi

Can I Grow Bok Choy in North Dakota?

USDA Zones 3b-4b · Plant zone range 2-11

Yes — Strong Match

bok choy is grown in zones 2-11, which covers every zone North Dakota contains (3b-4b). Whether the season is long enough is the question that remains.

Bok Choy in North Dakota — the short answer

Bok Choy in North Dakota: grown in zones 2–11, part sun, against a state median of ~157 frost-free days.

Plant zones
Grown as an annual — see the growing season
Growing season, not a hardiness zone
North Dakota zones
3b-4b
USDA PHZM 2023
Frost window
Apr 30 - May 6 – Oct 4 - Oct 9
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
141 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Days to maturity
45 days
Growable Ground Plant Database

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

Score your parcel · free to start

Your yard isn't the whole zone.

Bok Choy is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical North Dakota site runs ~157 frost-free days, but that is a state median, not your yard: slope, trees, and low spots move the last-frost date across a single parcel. Enter your address and we'll score bok choy against your land's actual frost dates, sun, and soil.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your parcel report in seconds — read in full free for your first 14 days

North Dakota is not one climate

North Dakota’s winter-low ladder runs across 53 counties, from zone 3.5 in Bottineau County to zone 4.5 in Stutsman County. That is 10°F between the two counties’ average coldest night — the difference between bok choy overwintering in the ground and coming under cover.

3.5 zonesBottineau County4.5 zonesStutsman County

The middle half of 53 counties runs 4–4 zones, with a median of 4 zones — a 1-zone span end to end.

Measured across 53 North Dakota counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Where in North Dakota Fits Best

Even within North Dakota's zones 3b-4b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for bok choy (USDA PHZM 2023):

Zone Comparison

Bok Choy Needs

  • USDA Zones: 2-11
  • Frost-Free Days: 21+
  • Sun: Part SunWe haven't confirmed this against a published source yet.
  • Mature size: 1 ft tallWe haven't confirmed this against a published source yet.
  • Picking window: ~14 days of harvestWe haven't confirmed this against a published source yet.
  • Drought tolerance: LowWe haven't confirmed this against a published source yet.

North Dakota Has

  • USDA Zones: 3b-4b
  • Last Hard Freeze (28°F): Apr 30 - May 6
  • First Hard Freeze (28°F): Oct 4 - Oct 9
  • Annual Rainfall: 14-22 inches
  • Common Soils: Prairie loam, Clay (Red River Valley), Sandy loam

Plant Zone Range (zones 2-11)

2a
11b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.0 – 7.5

We haven't confirmed this against a published source yet.

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Bok Choy in North Dakota

The frost window

Across North Dakota, the last spring hard freeze (28°F) clears between Apr 30 and May 6, and the first fall hard freeze lands between Oct 4 and Oct 9 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 151-day window you can count on — up to 162 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.

When to start the seed

Those dates are when bok choy goes out, not when it starts. It is sown under cover about 4 weeks ahead, so counting back from North Dakota's late-side last freeze of May 6 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.

Days to maturity vs. the window

At 45 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 106 days to spare even in North Dakota's tightest freeze scenario — room for a later start or a second sowing.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Growing Season Fit

Bok Choy is grown in zones 2–11, which covers every zone North Dakota contains (3b-4b). It is grown as a summer crop, so season length decides it here. North Dakota's typical season runs ~157 frost-free days against the ~21 bok choy needs.

Frost-free days

Bok Choy wants 21+ frost-free days; a typical North Dakota site sees ~157 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.

Growing degree days

Bok Choy needs ~1000 GDD (base 50°F) to ripen. We haven't confirmed this against a published source yet. The state median runs ~1913 GDD (from PRISM 1991-2020 climate normals), so North Dakota's typical season clears that easily.

GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.

Soil + Drainage Fit

Bok Choy likes near-neutral soil (pH 5-7.5). That's the common-ground band across North Dakota's prairie loam and clay (red river valley) — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 5.5 and 7 — worth knowing before you decide whether a North Dakota soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your North Dakota site is heavier clay or sits in a low spot, a raised bed lifts the roots above wet ground, or work in compost. pH range, preferred pH and drainage need: We haven't confirmed this against a published source yet.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. North Dakota soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Before you plant bok choy for food

Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before bok choy goes in. What follows is North Dakota’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.

Safe to Grow Here?

What the federal record shows across North Dakota — and how to grow with it.

Federal record: High

We checked the federal record across North Dakota — 4,130 documented sites across 5 of the 8 source types we track.

The most significant on record: 22 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

North Dakota carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds of imported, lab-tested soil grow well almost anywhere in the meantime.

Know before you grow — the guide

Sources Checked

across North Dakota

Severity Distribution

across North Dakota

High37Moderate1,115Low2,978

Highest-Severity Sites

Superfund · Superfund NPL
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected

A note from Gnorman

What an experienced grower watches for around here

In and around North Dakota, Brownfields runs higher than the national average — 345 sites across North Dakota. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.

Brownfields: Brownfield sites are former commercial or industrial properties that EPA’s Brownfields program (ACRES) has assessed or funded cleanup on.

Contact the EPA Brownfields program or the state cleanup agency for this site’s actual assessment/remediation status — ACRES itself does not publish one we can read per site.

Sources: EPA, USGS — 950K documented sites tracked nationwide across 8 federal source types.

What Else to Consider for Bok Choy in North Dakota

The zone range tells you where bok choy is grown — but North Dakota growers also need to think about:

Extreme cold (-40F) and short growing season

Persistent wind desiccates plants

Low rainfall in western ND

What to actually do about these — and the constraints that apply to every North Dakota grower, not just bok choy — is covered on the North Dakota growing guide.

Timing shifts within North Dakota

Bok Choy needs about 21 days of frost-free season to complete its cycle. Even Bottineau County — North Dakota’s shortest season at 141 frost-free days — clears that by 120 days, so season length isn’t the constraint anywhere in North Dakota. What varies is your own parcel.

County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Bok Choy's 21-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.

Pollinator + Wildlife Value

Bok Choy draws honeybees and native bees (moderate value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, bok choy can only work that bloom inside North Dakota's frost window — roughly 157 days, opening after the last 28°F freeze (Apr 30 - May 6) and closing at the first (Oct 4 - Oct 9), per NOAA Regional Climate Centers ACIS, 1991-2020. Pollinator value: We haven't confirmed this against a published source yet.

North Dakota Cooperative Extension

For North Dakota-specific cultivar recommendations, planting calendars, and pest pressure for bok choy, the canonical source is NDSU Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Bok Choy native to North Dakota?

No — the USDA PLANTS Database lists Bok Choy as introduced rather than native in the Lower 48, so it is not part of North Dakota's native flora. It grows here as a garden plant; pairing it with a few North Dakota natives keeps local pollinators fed too.

Looking for plants that belong here? The North Dakota growing guide lists plants that USDA PLANTS records growing in North Dakota and that Kew and NatureServe Explorer both list in its native range, leaving out any that NatureServe flags as exotic there or that our audit holds.

State records: USDA PLANTS Database state-distribution data (presence, not state-level nativity), accessed 2026-10-19.

Common Questions About Growing Bok Choy in North Dakota

When can I plant Bok Choy in North Dakota?

North Dakota's last spring hard freeze (28°F) clears between Apr 30 and May 6, and the first fall hard freeze lands between Oct 4 and Oct 9 (NOAA Regional Climate Centers ACIS, 1991-2020). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.

Can Bok Choy mature before first frost in North Dakota?

Yes — Bok Choy matures in 45 days (Growable Ground Plant Database), and North Dakota's dependable hard-freeze-free window runs 151 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 106 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.

What hardiness zone is Bok Choy grown in across North Dakota?

North Dakota spans USDA hardiness zones 3b-4b (USDA ARS PHZM 2023). Bok Choy carries a range of zones 2-11, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical North Dakota site have?

A typical North Dakota site sees ~157 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Bok Choy needs 21+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Bok Choy native to North Dakota?

No — the USDA PLANTS Database lists Bok Choy as introduced rather than native in the Lower 48, so it is not part of North Dakota's native flora. It grows here as a garden plant; pairing it with a few North Dakota natives keeps local pollinators fed too.

How should I amend the soil for Bok Choy in North Dakota?

Bok Choy prefers pH 5-7.5 and well (dry spells) drainage. We haven't confirmed this against a published source yet. That sits in the common-ground band across North Dakota soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will Bok Choy actually grow on my specific land in North Dakota?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores bok choy against your address's mapped soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free to start

Check your specific parcel in North Dakota

State-level data is a sketch. Your Growable Ground report scores bok choy against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.

Three things about your lot that North Dakota bok choy averages can't show:

Your soil pHYour frost-free days — North Dakota averages 157Your sun & shade

We read public map data around North Dakota — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the North Dakota bok choy average

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