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When to Plant Napa Cabbage in Green Lake County, WI

Green Lake County, Wisconsin Zone 4b April

Your April gardening checklist

Welcome to April in Zone 4b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 27
Avg. first frost October 14
Soil temp (4") 40°F
Watering Moderate
Pest pressure Low
Daylight 13.2 hrs
  1. Harden off and plant napa cabbage

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Direct-sow napa cabbage

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

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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.

Green Lake County, Wisconsin is in USDA Zone 4b. The average last spring frost is April 27 and the first fall frost is October 14, giving you a growing season of approximately 170 days.

At an elevation of 592 feet, Green Lake County receives approximately 32.7 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.

Green Lake County, WI (Zone 4b) Moderate season
170 days
Last Spring Frost April 27
170 growing days
First Fall Frost October 14
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Green Lake County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (77 days to spare)
Start indoors: Mar 12 Transplant: Apr 23 🍅 Harvest: Jun 18 – Jul 23
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Mar 16 Transplant: Apr 27 🍅 Harvest: Jun 22 – Jul 27
Safe Start (90%) ✓ Fits season (77 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 7 – Aug 11

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 Green Lake County

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

Soil pH

Your soil pH (6.2–7.1) is within Napa Cabbage's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.2%) — Napa Cabbage will thrive.

How to Plant Napa Cabbage

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Napa Cabbage

3
successive plantings in your 170-day season

Sow every 6.3 weeks. Last sowing by Jul 31 to harvest before frost.

For a dedicated fall crop, sow by Jul 22.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,257 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 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 6.5" 3.1" 3.4" 🚿 Regular watering
May 6.5" 3.5" 3" 💧 Light watering
Jun 6.5" 3.8" 2.7" 💧 Light watering
Jul 6.5" 4" 2.5" 💧 Light watering
Aug 6.5" 3.3" 3.2" 💧 Light watering
Sep 6.5" 3.1" 3.4" 🚿 Regular watering
Oct 6.5" 2.4" 4.1" 🚿 Regular watering
Nov 2.1" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Green Lake 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 2,210 GDD Excellent fit

Napa Cabbage Planting Timeline — Green Lake County, WI

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors April 27 Apr 27 – May 11
Direct Sow April 20 Apr 20 – May 11
Harvest June 22 Jun 22 – Jul 27
Fall Sowing July 22 Jul 22 – Aug 5

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 4b

📆 Growing Season

170 days in Green Lake County

Growing Tips for Napa Cabbage in Green Lake County

Direct sow Napa Cabbage outdoors after April 27 in Green Lake 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 Green Lake County, WI?

Green Lake County is in Zone 4b with an average last frost of April 27. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Green Lake County, WI?

Green Lake County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is April 27 and first fall frost is October 14.

🌱

Your Green Lake County Garden Planner — Free

A 24-page printable planner built for Green Lake 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 Green Lake County, WI. 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.