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When to Plant Komatsuna in Andrew County, MO

Andrew County, Missouri Zone 6a May

May in Andrew County, Missouri — your action list

We've pulled the most time-sensitive tasks for Andrew County, Missouri this May and put them front and centre. Tackle them in order.

Avg. last frost April 17
Avg. first frost October 18
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
  1. Time to start komatsuna inside

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Bring in the komatsuna

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Coming up in June — start thinking about
  • 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.

Andrew County, Missouri is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 18, giving you a growing season of approximately 184 days.

At an elevation of 1,292 feet, Andrew County receives approximately 37.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Komatsuna during the growing season.

Andrew County, MO (Zone 6a) Moderate season
184 days
Last Spring Frost April 17
184 growing days
First Fall Frost October 18

Andrew County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: May 17 – Jun 21
Recommended (50%) ✓ Fits season (114 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: May 22 – Jun 26
Safe Start (90%) ✓ Fits season (115 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jun 4 – Jul 9

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 Andrew County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Komatsuna's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). 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

6
successive plantings in your 184-day season

Sow every 4 weeks. Last sowing by Aug 29 to harvest before frost.

For a dedicated fall crop, sow by Aug 09.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 240 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 1.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Andrew 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 ~584 GDD — county provides 2,530 GDD Excellent fit

Komatsuna Planting Timeline — Andrew County, MO

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 – Mar 27
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 3 Apr 3 – Apr 24
Harvest May 22 May 22 – Jun 26
Fall Sowing August 9 Aug 9 – Aug 23

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

Month-by-Month Timeline

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

📆 Growing Season

184 days in Andrew County

Growing Tips for Komatsuna in Andrew County

Direct sow Komatsuna outdoors after April 17 in Andrew County when soil has warmed and frost danger has passed.

Your generous 184.0-day season in Andrew 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 Andrew County, MO?

Andrew County is in Zone 6a with an average last frost of April 17. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Andrew County, MO?

Andrew County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 18.

🌱

Your Andrew County Garden Planner — Free

A 24-page printable planner built for Andrew County (Zone 6a). 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 Andrew County, MO. 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.