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When to Plant Komatsuna in Charlevoix County, MI

Charlevoix County, Michigan Zone 6a May

Your May gardening checklist

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Charlevoix County, Michigan.

Avg. last frost May 5
Avg. first frost October 21
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Get komatsuna in the ground

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

Before June arrives, get these ready
  • Starting indoors: komatsuna
  • 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.

Charlevoix County, Michigan is in USDA Zone 6a. The average last spring frost is May 5 and the first fall frost is October 21, giving you a growing season of approximately 169 days.

At an elevation of 821 feet, Charlevoix County receives approximately 41.9 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.

Charlevoix County, MI (Zone 6a) Moderate season
169 days
Last Spring Frost May 5
169 growing days
First Fall Frost October 21

Charlevoix County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (94 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 1 – Jul 6
Recommended (50%) ✓ Fits season (99 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 9 – Jul 14
Safe Start (90%) ✓ Fits season (99 days to spare)
Start indoors: Apr 15 Transplant: May 20 🍅 Harvest: Jun 24 – Jul 29

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 Charlevoix County

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

Soil pH

Your soil pH (6.0–6.8) is within Komatsuna's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — 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

5
successive plantings in your 169-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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.7" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 3.7" 0" ❄️ Dormant
May 4.3" 5.3" 0" ✅ Rainfall sufficient
Jun 4.3" 5.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 4.1" 0.2" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Charlevoix 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 2,197 GDD Excellent fit

Komatsuna Planting Timeline — Charlevoix County, MI

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 – Apr 14
Transplant Outdoors May 5 May 5 – May 19
Direct Sow April 21 Apr 21 – May 12
Harvest June 9 Jun 9 – Jul 14
Fall Sowing August 12 Aug 12 – Aug 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

169 days in Charlevoix County

Growing Tips for Komatsuna in Charlevoix County

Direct sow Komatsuna outdoors after May 05 in Charlevoix County when soil has warmed and frost danger has passed.

Your generous 169.0-day season in Charlevoix 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 Charlevoix County, MI?

Charlevoix County is in Zone 6a with an average last frost of May 5. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Charlevoix County, MI?

Charlevoix County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is May 5 and first fall frost is October 21.

🌱

Your Charlevoix County Garden Planner — Free

A 24-page printable planner built for Charlevoix 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 Charlevoix County, MI. 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.