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When to Plant Komatsuna in Auglaize 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.

Auglaize County, Ohio is in USDA Zone 5b. The average last spring frost is April 25 and the first fall frost is October 21, giving you a growing season of approximately 179 days.

At an elevation of 691 feet, Auglaize County receives approximately 31.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Komatsuna to ensure they mature before fall.

Auglaize County, OH (Zone 5b) Moderate season
179 days
Last Spring Frost April 25
179 growing days
First Fall Frost October 21

Auglaize County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (112 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: May 22 – Jun 26
Recommended (50%) ✓ Fits season (109 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: May 30 – Jul 4
Safe Start (90%) ✓ Fits season (106 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jun 12 – Jul 17

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
0.3″/week
Watering frequency Only during dry spells
Season total 404 gal / 100 sq ft
Komatsuna needs ~521 GDD — county provides 2,192 GDD Excellent fit

Komatsuna Planting Timeline โ€” Auglaize County, OH

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 โ€“ Apr 4
Transplant Outdoors April 25 Apr 25 โ€“ May 9
Direct Sow April 11 Apr 11 โ€“ May 2
Fall Sowing August 12 Aug 12 โ€“ Aug 26
Harvest May 30 May 30 โ€“ Jul 4

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 Harvest
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

179 days

Growing Tips for Auglaize 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 Auglaize County, OH?

Auglaize County is in Zone 5b with an average last frost of April 25. Plan your Komatsuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Auglaize County, OH?

Auglaize County, Ohio is in USDA Hardiness Zone 5b. The average last spring frost is April 25 and first fall frost is October 21.

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Plan Your Garden with Confidence

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