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When to Plant Bok Choy in Sioux County, ND

Bok choy is a Chinese cabbage variety with crisp white stalks and dark green leaves. It is a fast-growing cool-season crop ideal for stir-fries and soups.

Sioux County, North Dakota is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is October 1, giving you a growing season of approximately 142 days.

At an elevation of 1,012 feet, Sioux County receives approximately 32.3 inches of rainfall annually with predominantly loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Bok Choy to ensure they mature before fall.

Sioux County, ND (Zone 4a) Short season
142 days
Last Spring Frost May 12
142 growing days
First Fall Frost October 1

Sioux County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (65 days to spare)
Start indoors: Mar 23 Transplant: May 4 🍅 Harvest: Jun 15 – Jul 20
Recommended (50%) ✓ Fits season (65 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jun 23 – Jul 28
Safe Start (90%) ✓ Fits season (68 days to spare)
Start indoors: Apr 7 Transplant: May 19 🍅 Harvest: Jun 30 – Aug 4

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 826 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Bok Choy needs ~575 GDD — county provides 1,633 GDD Excellent fit

Bok Choy Planting Timeline โ€” Sioux County, ND

Bok Choy Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 โ€“ Apr 14
Transplant Outdoors May 12 May 12 โ€“ May 26
Direct Sow May 5 May 5 โ€“ May 26
Fall Sowing July 9 Jul 9 โ€“ Jul 23
Harvest June 23 Jun 23 โ€“ Jul 28

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

40โ€“60 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 4a

Growing Season

142 days

Growing Tips for Sioux County

Direct sow in spring or fall for best results. Keep soil consistently moist. Harvest whole heads or cut outer leaves for a cut-and-come-again approach.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Bok Choy in Sioux County, ND?

Sioux County is in Zone 4a with an average last frost of May 12. Plan your Bok Choy planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sioux County, ND?

Sioux County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 12 and first fall frost is October 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sioux County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Sioux County, ND. Local conditions may vary. Last updated: April 2026.