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When to Plant Napa Cabbage in Montmorency County, MI

Montmorency County, Michigan Zone 5a April

Your April planting checklist for Montmorency County, Michigan

Welcome to April in Zone 5a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 19
Avg. first frost October 1
Soil temp (4") 41°F
Watering Low
Pest pressure Low
Daylight 13.3 hrs
Get ahead of May
  • Transplants going out: napa cabbage
  • Direct-sowing: napa cabbage

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Napa cabbage forms tall, barrel-shaped heads with tender, crinkled leaves and a mild, slightly sweet flavor. It is the primary cabbage used for kimchi.

Montmorency County, Michigan is in USDA Zone 4b. The average last spring frost is May 19 and the first fall frost is October 1, giving you a growing season of approximately 135 days.

At an elevation of 1,107 feet, Montmorency County receives approximately 40.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Napa Cabbage to ensure they mature before fall.

Montmorency County, MI (Zone 4b) Short season
135 days
Last Spring Frost May 19
135 growing days
First Fall Frost October 1
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Montmorency County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (42 days to spare)
Start indoors: Apr 10 Transplant: May 15 🍅 Harvest: Jul 10 – Aug 14
Recommended (50%) ✓ Fits season (44 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Jul 14 – Aug 18
Safe Start (90%) ✓ Fits season (46 days to spare)
Start indoors: Apr 28 Transplant: Jun 2 🍅 Harvest: Jul 28 – Sep 1

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 Montmorency County

How your county's soil matches Napa Cabbage's growing requirements.

Soil pH

Your soil pH (6.1–6.8) is within Napa Cabbage's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Napa Cabbage will thrive.

How to Plant Napa Cabbage

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Succession Planting Napa Cabbage

2
successive plantings in your 135-day season

Sow every 6.3 weeks. Last sowing by Jul 18 to harvest before frost.

For a dedicated fall crop, sow by Jul 23.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.3″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 288 gal / 100 sq ft

Monthly Watering Guide for Napa Cabbage

Napa Cabbage needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Napa Cabbage Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.1" 0" ❄️ Dormant
May 6.5" 4.3" 2.2" 💧 Light watering
Jun 6.5" 5.6" 0.9" 💧 Light watering
Jul 6.5" 4.2" 2.3" 💧 Light watering
Aug 6.5" 4.7" 1.8" 💧 Light watering
Sep 6.5" 3.4" 3.1" 💧 Light watering
Oct 6.5" 3.2" 3.3" 🚿 Regular watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Montmorency County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Napa Cabbage 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.

Napa Cabbage needs ~796 GDD — county provides 1,653 GDD Excellent fit

Napa Cabbage Planting Timeline — Montmorency County, MI

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors May 19 May 19 – Jun 2
Direct Sow May 12 May 12 – Jun 2
Harvest July 14 Jul 14 – Aug 18
Fall Sowing July 9 Jul 9 – Jul 23

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 4b

📆 Growing Season

135 days in Montmorency County

Growing Tips for Napa Cabbage in Montmorency County

Direct sow Napa Cabbage outdoors after May 19 in Montmorency County when soil has warmed and frost danger has passed.

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

General growing tips

Best grown as a fall crop. Direct sow in late summer, 60-70 days before first frost. Keep soil evenly moist. Bolt-resistant varieties are available for spring planting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Napa Cabbage in Montmorency County, MI?

Montmorency County is in Zone 4b with an average last frost of May 19. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Montmorency County, MI?

Montmorency County, Michigan is in USDA Hardiness Zone 4b. The average last spring frost is May 19 and first fall frost is October 1.

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Your Montmorency County Garden Planner — Free

A 24-page printable planner built for Montmorency County (Zone 4b). 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 Montmorency County, MI. Local conditions may vary. Last updated: April 2026.

Sources & credits

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