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When to Plant Komatsuna in Montgomery 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.

Montgomery County, Ohio is in USDA Zone 6a. The average last spring frost is April 19 and the first fall frost is October 21, giving you a growing season of approximately 185 days.

At an elevation of 633 feet, Montgomery County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Komatsuna during the growing season.

Montgomery County, OH (Zone 6a) Moderate season
185 days
Last Spring Frost April 19
185 growing days
First Fall Frost October 21

Montgomery County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (118 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: May 16 – Jun 20
Recommended (50%) ✓ Fits season (115 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🍅 Harvest: May 24 – Jun 28
Safe Start (90%) ✓ Fits season (108 days to spare)
Start indoors: Apr 4 Transplant: May 9 🍅 Harvest: Jun 13 – Jul 18

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.

Soil Compatibility in Montgomery County

How your county's soil matches Komatsuna's growing requirements.

Soil pH

Your soil pH (5.7โ€“7.1) overlaps with Komatsuna's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The silt loam soil in Montgomery County is excellent for Komatsuna โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.8%) โ€” Komatsuna will thrive.

How to Plant Komatsuna

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Komatsuna

6
successive plantings in your 185-day season

Sow every 4 weeks. Last sowing by Sep 01 to harvest before frost.

For a dedicated fall crop, sow by Aug 12.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 163 gal / 100 sq ft

Monthly Watering Guide for Komatsuna

Komatsuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Komatsuna Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.5" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
May 4.3" 5" 0" โœ… Rainfall sufficient
Jun 4.3" 4.9" 0" โœ… Rainfall sufficient
Jul 4.3" 4.9" 0" โœ… Rainfall sufficient
Aug 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Sep 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Oct 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Nov โ€” 2.8" 0" โ„๏ธ Dormant
Dec โ€” 2.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Montgomery County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Komatsuna Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Komatsuna needs ~680 GDD — county provides 2,960 GDD Excellent fit

Komatsuna Planting Timeline โ€” Montgomery County, OH

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 โ€“ Mar 29
Transplant Outdoors April 19 Apr 19 โ€“ May 3
Direct Sow April 5 Apr 5 โ€“ Apr 26
Harvest May 24 May 24 โ€“ Jun 28
Fall Sowing August 12 Aug 12 โ€“ Aug 26

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

35โ€“50 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

185 days in Montgomery County

Growing Tips for Komatsuna in Montgomery County

Direct sow Komatsuna outdoors after April 19 in Montgomery County when soil has warmed and frost danger has passed.

Your generous 185.0-day season in Montgomery County allows multiple plantings of Komatsuna. Sow every 17.0 days for continuous harvest.

Common pests for Komatsuna in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Komatsuna in Montgomery County, OH?

Montgomery County is in Zone 6a with an average last frost of April 19. Plan your Komatsuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Montgomery County, OH?

Montgomery County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 19 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Montgomery County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Montgomery County, OH. Local conditions may vary. Last updated: April 2026.