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When to Plant Komatsuna in Ouachita County, AR

Ouachita County, Arkansas Zone 8a May

What to do in May

Your Ouachita County, Arkansas garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 23
Avg. first frost November 3
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Bring in the komatsuna

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

A few tasks this May that'll pay off in June
  • First harvests: komatsuna

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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.

Ouachita County, Arkansas is in USDA Zone 8a. The average last spring frost is March 23 and the first fall frost is November 3, giving you a growing season of approximately 225 days.

At an elevation of 591 feet, Ouachita County receives approximately 48.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 95°F, so Komatsuna may need afternoon shade and extra watering during peak heat.

Ouachita County, AR (Zone 8a) Long season
225 days
Last Spring Frost March 23
225 growing days
First Fall Frost November 3

Ouachita County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (160 days to spare)
Start indoors: Feb 6 Transplant: Mar 13 🍅 Harvest: Apr 17 – May 22
Recommended (50%) ✓ Fits season (155 days to spare)
Start indoors: Feb 16 Transplant: Mar 23 🍅 Harvest: Apr 27 – Jun 1
Safe Start (90%) ✓ Fits season (154 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🍅 Harvest: May 19 – Jun 23

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 Ouachita County

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

Soil pH

Your soil pH (5.6–7.1) overlaps with Komatsuna's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Ouachita County is excellent for Komatsuna — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Komatsuna.

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

7
successive plantings in your 225-day season

Sow every 4 weeks. Last sowing by Sep 14 to harvest before frost.

For a dedicated fall crop, sow by Aug 25.

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 178 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 4.2" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 4.3" 4.4" 0" ✅ Rainfall sufficient
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 5.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.8" 0" ✅ Rainfall sufficient
Sep 4.3" 4.1" 0.2" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 4" 0.3" 💧 Light watering
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Ouachita County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~903 GDD — county provides 4,781 GDD Excellent fit

Komatsuna Planting Timeline — Ouachita County, AR

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 – Mar 2
Transplant Outdoors March 23 Mar 23 – Apr 6
Direct Sow March 9 Mar 9 – Mar 30
Harvest April 27 Apr 27 – Jun 1
Fall Sowing August 25 Aug 25 – Sep 8

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

225 days in Ouachita County

Growing Tips for Komatsuna in Ouachita County

Direct sow Komatsuna outdoors after March 23 in Ouachita County when soil has warmed and frost danger has passed.

Your generous 225.0-day season in Ouachita 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 Ouachita County, AR?

Ouachita County is in Zone 8a with an average last frost of March 23. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ouachita County, AR?

Ouachita County, Arkansas is in USDA Hardiness Zone 8a. The average last spring frost is March 23 and first fall frost is November 3.

🌱

Your Ouachita County Garden Planner — Free

A 24-page printable planner built for Ouachita County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Ouachita County, AR. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.