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When to Plant Komatsuna in Steele County, ND

Komatsuna (Japanese mustard spinach) is a versatile Asian green with glossy, dark leaves and a mild, sweet flavor. It is extremely cold-hardy and heat-tolerant.

Steele County, North Dakota is in USDA Zone 3b. The average last spring frost is May 11 and the first fall frost is October 1, giving you a growing season of approximately 143 days.

At an elevation of 624 feet, Steele County receives approximately 21.9 inches of rainfall annually with predominantly loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Komatsuna to ensure they mature before fall.

Steele County, ND (Zone 3b) Short season
143 days
Last Spring Frost May 11
143 growing days
First Fall Frost October 1

Steele County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (73 days to spare)
Start indoors: Mar 26 Transplant: May 7 🍅 Harvest: Jun 11 – Jul 16
Recommended (50%) ✓ Fits season (73 days to spare)
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Jun 15 – Jul 20
Safe Start (90%) ✓ Fits season (74 days to spare)
Start indoors: Apr 11 Transplant: May 23 🍅 Harvest: Jun 27 – Aug 1

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
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 545 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Komatsuna needs ~425 GDD — county provides 1,430 GDD Excellent fit

Komatsuna Planting Timeline โ€” Steele County, ND

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 โ€“ Apr 13
Transplant Outdoors May 11 May 11 โ€“ May 25
Direct Sow May 4 May 4 โ€“ May 25
Fall Sowing July 9 Jul 9 โ€“ Jul 23
Harvest June 15 Jun 15 โ€“ Jul 20

Plant 0.5" deep ยท 6" apart ยท Rows 12" 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

Moderate โ€” regular watering

Days to Maturity

35โ€“50 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 3b

Growing Season

143 days

Growing Tips for Steele County

Direct sow in spring or fall. One of the most forgiving Asian greens for all seasons. Harvest outer leaves or cut whole plants. Excellent for stir-fries, soups, or salads.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Komatsuna in Steele County, ND?

Steele County is in Zone 3b with an average last frost of May 11. Plan your Komatsuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Steele County, ND?

Steele County, North Dakota is in USDA Hardiness Zone 3b. The average last spring frost is May 11 and first fall frost is October 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Steele County gardeners in Zone 3b 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 Steele County, ND. Local conditions may vary. Last updated: April 2026.