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When to Plant Napa Cabbage in Wells County, ND

Wells County, North Dakota Zone 4a May

Your May gardening checklist

Your garden in Wells County, North Dakota is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 11
Avg. first frost September 29
Soil temp (4") 52°F
Watering Low
Pest pressure Low
Daylight 14.9 hrs
  1. Plant out napa cabbage

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Plant napa cabbage from seed, right in the garden

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

Looking ahead to June
  • Starting indoors: 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.

Wells County, North Dakota is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is September 29, giving you a growing season of approximately 141 days.

At an elevation of 796 feet, Wells County receives approximately 29.3 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Napa Cabbage to ensure they mature before fall.

Wells County, ND (Zone 4a) Short season
141 days
Last Spring Frost May 11
141 growing days
First Fall Frost September 29

Wells County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (51 days to spare)
Start indoors: Mar 22 Transplant: May 3 🍅 Harvest: Jun 28 – Aug 2
Recommended (50%) ✓ Fits season (50 days to spare)
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Jul 6 – Aug 10
Safe Start (90%) ✓ Fits season (53 days to spare)
Start indoors: Apr 8 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 Wells County

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

Soil pH

Your soil pH (6.3–7.8) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Napa Cabbage.

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

2
successive plantings in your 141-day season

Sow every 6.3 weeks. Last sowing by Jul 16 to harvest before frost.

For a dedicated fall crop, sow by Jul 07.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 787 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 0.7" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 3" 0" ❄️ Dormant
May 6.5" 4.8" 1.7" 💧 Light watering
Jun 6.5" 5.1" 1.4" 💧 Light watering
Jul 6.5" 3.6" 2.9" 💧 Light watering
Aug 6.5" 3.6" 2.9" 💧 Light watering
Sep 6.5" 2.6" 3.9" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Wells 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 ~650 GDD — county provides 1,410 GDD Excellent fit

Napa Cabbage Planting Timeline — Wells County, ND

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 – Apr 13
Transplant Outdoors May 11 May 11 – May 25
Direct Sow May 4 May 4 – May 25
Harvest July 6 Jul 6 – Aug 10
Fall Sowing July 7 Jul 7 – Jul 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

141 days in Wells County

Growing Tips for Napa Cabbage in Wells County

Direct sow Napa Cabbage outdoors after May 11 in Wells 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 Wells County, ND?

Wells County is in Zone 4a with an average last frost of May 11. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wells County, ND?

Wells County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is September 29.

🌱

Your Wells County Garden Planner — Free

A 24-page printable planner built for Wells County (Zone 4a). 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 Wells County, ND. Local conditions may vary. Last updated: May 2026.

Sources & credits

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