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When to Plant Napa Cabbage in Swain County, NC

Swain County, North Carolina Zone 7a May

What to do in May

Welcome to May in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 24
Avg. first frost October 17
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 13.9 hrs
  1. Get napa cabbage seeds going inside

    Label every cell. You will absolutely forget which is which otherwise.

June prep starts now
  • First harvests: 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.

Swain County, North Carolina is in USDA Zone 7a. The average last spring frost is April 24 and the first fall frost is October 17, giving you a growing season of approximately 176 days.

At an elevation of 2,612 feet, Swain County receives approximately 47.6 inches of rainfall annually with predominantly clay loam soil. Summer highs average 86°F, providing good warmth for Napa Cabbage during the growing season. Clay soil retains moisture well for Napa Cabbage, but amend with compost to improve drainage and prevent root rot.

Swain County, NC (Zone 7a) Moderate season
176 days
Last Spring Frost April 24
176 growing days
First Fall Frost October 17
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Swain County Soil Profile

Soil Type

Clay Loam

Soil pH

5.4-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (91 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jun 12 – Jul 17
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: Jun 19 – Jul 24
Safe Start (90%) ✓ Fits season (83 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jul 3 – Aug 7

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 Swain County

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

Soil pH

Your soil pH (5.4–6.7) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Napa Cabbage.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Napa Cabbage.

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 176-day season

Sow every 6.3 weeks. Last sowing by Aug 03 to harvest before frost.

For a dedicated fall crop, sow by Aug 08.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.1″/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 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 3.8" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 4.7" 0" ❄️ Dormant
Apr 6.5" 4" 2.5" 💧 Light watering
May 6.5" 4.3" 2.2" 💧 Light watering
Jun 6.5" 4.7" 1.8" 💧 Light watering
Jul 6.5" 4.8" 1.7" 💧 Light watering
Aug 6.5" 3.9" 2.6" 💧 Light watering
Sep 6.5" 3.1" 3.4" 🚿 Regular watering
Oct 6.5" 2.9" 3.6" 🚿 Regular watering
Nov 3.5" 0" ❄️ Dormant
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Swain 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 ~942 GDD — county provides 2,552 GDD Excellent fit

Napa Cabbage Planting Timeline — Swain County, NC

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors April 24 Apr 24 – May 8
Direct Sow April 10 Apr 10 – May 1
Harvest June 19 Jun 19 – Jul 24
Fall Sowing August 8 Aug 8 – Aug 22

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
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · Natural rainfall sufficient

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

176 days in Swain County

Growing Tips for Napa Cabbage in Swain County

Direct sow Napa Cabbage outdoors after April 24 in Swain County when soil has warmed and frost danger has passed.

With Swain County's clay soil (31% clay), work in 3-4 inches of compost before planting Napa Cabbage. Avoid tilling when soil is wet to prevent compaction.

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 Swain County, NC?

Swain County is in Zone 7a with an average last frost of April 24. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Swain County, NC?

Swain County, North Carolina is in USDA Hardiness Zone 7a. The average last spring frost is April 24 and first fall frost is October 17.

🌱

Your Swain County Garden Planner — Free

A 24-page printable planner built for Swain County (Zone 7a). 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 Swain County, NC. 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.