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When to Plant Komatsuna in Menard County, IL

Menard County, Illinois Zone 6a May

May to-do list for Menard County, Illinois

Here's what deserves your attention in Menard County, Illinois this month. Everything below is tailored to Zone 6a and timed around your local frost dates.

Avg. last frost April 15
Avg. first frost October 19
Soil temp (4") 59°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
  1. Indoor seed-starting week for komatsuna

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. Collect komatsuna at their peak

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

Before June arrives, get these ready
  • 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.

Menard County, Illinois is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 19, giving you a growing season of approximately 187 days.

At an elevation of 934 feet, Menard County receives approximately 37 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Komatsuna to ensure they mature before fall.

Menard County, IL (Zone 6a) Moderate season
187 days
Last Spring Frost April 15
187 growing days
First Fall Frost October 19
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Menard County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (115 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: May 14 – Jun 18
Recommended (50%) ✓ Fits season (117 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 20 – Jun 24
Safe Start (90%) ✓ Fits season (114 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 Menard County

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

Soil pH

Your soil pH (6.2–7.0) is within Komatsuna's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — 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 187-day season

Sow every 4 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 10.

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 281 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 1.8" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Menard 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 ~552 GDD — county provides 2,431 GDD Excellent fit

Komatsuna Planting Timeline — Menard County, IL

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 – Mar 25
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 1 Apr 1 – Apr 22
Harvest May 20 May 20 – Jun 24
Fall Sowing August 10 Aug 10 – Aug 24

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 Harvest
June Harvest
July
August Fall Sowing
September
October
November
December
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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: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

187 days in Menard County

Growing Tips for Komatsuna in Menard County

Direct sow Komatsuna outdoors after April 15 in Menard County when soil has warmed and frost danger has passed.

Your generous 187.0-day season in Menard 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 Menard County, IL?

Menard County is in Zone 6a with an average last frost of April 15. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Menard County, IL?

Menard County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 19.

🌱

Your Menard County Garden Planner — Free

A 24-page printable planner built for Menard 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 Menard County, IL. 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.