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When to Plant Komatsuna in Alfalfa County, OK

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.

Alfalfa County, Oklahoma is in USDA Zone 6b. The average last spring frost is April 7 and the first fall frost is October 31, giving you a growing season of approximately 207 days.

At an elevation of 835 feet, Alfalfa County receives approximately 26.3 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Komatsuna during the growing season.

Alfalfa County, OK (Zone 6b) Long season
207 days
Last Spring Frost April 7
207 growing days
First Fall Frost October 31

Alfalfa County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (137 days to spare)
Start indoors: Feb 23 Transplant: Mar 30 🍅 Harvest: May 4 – Jun 8
Recommended (50%) ✓ Fits season (137 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: May 12 – Jun 16
Safe Start (90%) ✓ Fits season (141 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: May 26 – Jun 30

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
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,031 gal / 100 sq ft
Drought risk

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

Komatsuna needs ~584 GDD — county provides 2,846 GDD Excellent fit

Komatsuna Planting Timeline โ€” Alfalfa County, OK

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 โ€“ Mar 17
Transplant Outdoors April 7 Apr 7 โ€“ Apr 21
Direct Sow March 24 Mar 24 โ€“ Apr 14
Fall Sowing August 22 Aug 22 โ€“ Sep 5
Harvest May 12 May 12 โ€“ Jun 16

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July โ€”
August Fall Sowing
September Fall Sowing
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 6b

Growing Season

207 days

Growing Tips for Alfalfa 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 Alfalfa County, OK?

Alfalfa County is in Zone 6b with an average last frost of April 7. Plan your Komatsuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Alfalfa County, OK?

Alfalfa County, Oklahoma is in USDA Hardiness Zone 6b. The average last spring frost is April 7 and first fall frost is October 31.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Alfalfa County gardeners in Zone 6b 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 Alfalfa County, OK. Local conditions may vary. Last updated: April 2026.