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When to Plant Komatsuna in Huron County, OH

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.

Huron County, Ohio is in USDA Zone 5b. The average last spring frost is April 27 and the first fall frost is October 18, giving you a growing season of approximately 174 days.

At an elevation of 1,242 feet, Huron County receives approximately 32.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Komatsuna during the growing season.

Huron County, OH (Zone 5b) Moderate season
174 days
Last Spring Frost April 27
174 growing days
First Fall Frost October 18

Huron County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (102 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: May 28 – Jul 2
Recommended (50%) ✓ Fits season (104 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 1 – Jul 6
Safe Start (90%) ✓ Fits season (101 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jun 17 – Jul 22

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
0.2″/week
Watering frequency Only during dry spells
Season total 326 gal / 100 sq ft
Komatsuna needs ~648 GDD — county provides 2,653 GDD Excellent fit

Komatsuna Planting Timeline โ€” Huron County, OH

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 โ€“ Apr 6
Transplant Outdoors April 27 Apr 27 โ€“ May 11
Direct Sow April 13 Apr 13 โ€“ May 4
Fall Sowing August 9 Aug 9 โ€“ Aug 23
Harvest June 1 Jun 1 โ€“ Jul 6

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 Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Fall Sowing
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 5b

Growing Season

174 days

Growing Tips for Huron 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 Huron County, OH?

Huron County is in Zone 5b with an average last frost of April 27. Plan your Komatsuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Huron County, OH?

Huron County, Ohio is in USDA Hardiness Zone 5b. The average last spring frost is April 27 and first fall frost is October 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Huron County gardeners in Zone 5b 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 Huron County, OH. Local conditions may vary. Last updated: April 2026.