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When to Plant Komatsuna in Richland 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.

Richland County, North Dakota is in USDA Zone 4a. The average last spring frost is May 6 and the first fall frost is October 6, giving you a growing season of approximately 153 days.

At an elevation of 791 feet, Richland County receives approximately 28.3 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Komatsuna to ensure they mature before fall.

Richland County, ND (Zone 4a) Moderate season
153 days
Last Spring Frost May 6
153 growing days
First Fall Frost October 6

Richland County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Start indoors: Mar 16 Transplant: Apr 27 🍅 Harvest: Jun 1 – Jul 6
Recommended (50%) ✓ Fits season (83 days to spare)
Start indoors: Mar 25 Transplant: May 6 🍅 Harvest: Jun 10 – Jul 15
Safe Start (90%) ✓ Fits season (82 days to spare)
Start indoors: Apr 5 Transplant: May 17 🍅 Harvest: Jun 21 – Jul 26

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
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 855 gal / 100 sq ft
Drought risk

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

Komatsuna needs ~457 GDD — county provides 1,644 GDD Excellent fit

Komatsuna Planting Timeline โ€” Richland County, ND

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 โ€“ Apr 8
Transplant Outdoors May 6 May 6 โ€“ May 20
Direct Sow April 29 Apr 29 โ€“ May 20
Fall Sowing July 14 Jul 14 โ€“ Jul 28
Harvest June 10 Jun 10 โ€“ Jul 15

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 Direct Sow
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 4a

Growing Season

153 days

Growing Tips for Richland 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 Richland County, ND?

Richland County is in Zone 4a with an average last frost of May 6. Plan your Komatsuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Richland County, ND?

Richland County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 6 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Richland 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 Richland County, ND. Local conditions may vary. Last updated: April 2026.