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When to Plant Napa Cabbage in Clinton County, MI

Clinton County, Michigan Zone 6a April

April in the garden — Clinton County, Michigan

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

Avg. last frost April 30
Avg. first frost October 13
Soil temp (4") 43°F
Watering Moderate
Pest pressure Low
Daylight 13.2 hrs
  1. Move napa cabbage from tray to bed

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

  2. Outdoor sowing time: napa cabbage

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

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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.

Clinton County, Michigan is in USDA Zone 5b. The average last spring frost is April 30 and the first fall frost is October 13, giving you a growing season of approximately 166 days.

At an elevation of 519 feet, Clinton County receives approximately 34.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Napa Cabbage to ensure they mature before fall.

Clinton County, MI (Zone 5b) Moderate season
166 days
Last Spring Frost April 30
166 growing days
First Fall Frost October 13

Clinton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (71 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 22 – Jul 27
Recommended (50%) ✓ Fits season (75 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jun 25 – Jul 30
Safe Start (90%) ✓ Fits season (71 days to spare)
Start indoors: Apr 15 Transplant: May 20 🍅 Harvest: Jul 15 – Aug 19

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 Clinton County

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

Soil pH

Your soil pH (5.9–6.7) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Napa Cabbage is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is excellent (4.8%) — 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

3
successive plantings in your 166-day season

Sow every 6.3 weeks. Last sowing by Jul 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 04.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
1.3″/week
Watering frequency 2-3 times/week
Season total 1,928 gal / 100 sq ft
Drought risk

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

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 1.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 6.5" 2.9" 3.6" 🚿 Regular watering
May 6.5" 3.8" 2.7" 💧 Light watering
Jun 6.5" 4.1" 2.4" 💧 Light watering
Jul 6.5" 3.7" 2.8" 💧 Light watering
Aug 6.5" 3.9" 2.6" 💧 Light watering
Sep 6.5" 3" 3.5" 🚿 Regular watering
Oct 6.5" 2.7" 3.8" 🚿 Regular watering
Nov 2.5" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clinton 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 ~845 GDD — county provides 2,158 GDD Excellent fit

Napa Cabbage Planting Timeline — Clinton County, MI

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 16 Apr 16 – May 7
Harvest June 25 Jun 25 – Jul 30
Fall Sowing August 4 Aug 4 – Aug 18

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors 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

1.5"/week · 2-3 times/week

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

166 days in Clinton County

Growing Tips for Napa Cabbage in Clinton County

Direct sow Napa Cabbage outdoors after April 30 in Clinton 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 Clinton County, MI?

Clinton County is in Zone 5b with an average last frost of April 30. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clinton County, MI?

Clinton County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is April 30 and first fall frost is October 13.

🌱

Your Clinton County Garden Planner — Free

A 24-page printable planner built for Clinton County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Clinton 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.