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When to Plant Napa Cabbage in Shelby County, TN

Shelby County, Tennessee Zone 8a May

Shelby County, Tennessee gardeners: here's your May plan

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 21
Avg. first frost November 5
Soil temp (4") 60°F
Watering Moderate
Pest pressure Moderate
Daylight 13.8 hrs
  1. Collect napa cabbage at their peak

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Get ahead of June
  • 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.

Shelby County, Tennessee is in USDA Zone 8a. The average last spring frost is March 21 and the first fall frost is November 5, giving you a growing season of approximately 229 days.

At an elevation of 3,465 feet, Shelby County receives approximately 45.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Napa Cabbage during the growing season.

Shelby County, TN (Zone 8a) Long season
229 days
Last Spring Frost March 21
229 growing days
First Fall Frost November 5
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Shelby County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (141 days to spare)
Start indoors: Feb 7 Transplant: Mar 14 🍅 Harvest: May 9 – Jun 13
Recommended (50%) ✓ Fits season (138 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: May 16 – Jun 20
Safe Start (90%) ✓ Fits season (138 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 5 – Jul 10

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 Shelby County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). 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

4
successive plantings in your 229-day season

Sow every 6.3 weeks. Last sowing by Aug 22 to harvest before frost.

For a dedicated fall crop, sow by Aug 27.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,349 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 3.3" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 6.5" 4.2" 2.3" 💧 Light watering
Apr 6.5" 2.9" 3.6" 🚿 Regular watering
May 6.5" 3.6" 2.9" 💧 Light watering
Jun 6.5" 4.6" 1.9" 💧 Light watering
Jul 6.5" 5.1" 1.4" 💧 Light watering
Aug 6.5" 4.7" 1.8" 💧 Light watering
Sep 6.5" 3" 3.5" 🚿 Regular watering
Oct 6.5" 3.3" 3.2" 💧 Light watering
Nov 6.5" 3.5" 3" 💧 Light watering
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Shelby 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 ~1,089 GDD — county provides 3,835 GDD Excellent fit

Napa Cabbage Planting Timeline — Shelby County, TN

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors February 14 Feb 14 – Feb 28
Transplant Outdoors March 21 Mar 21 – Apr 4
Direct Sow March 7 Mar 7 – Mar 28
Harvest May 16 May 16 – Jun 20
Fall Sowing August 27 Aug 27 – Sep 10

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Transplant Outdoors Direct Sow
April Transplant Outdoors
May Harvest
June Harvest
July
August Fall Sowing
September Fall Sowing
October
November
December
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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 8a

📆 Growing Season

229 days in Shelby County

Growing Tips for Napa Cabbage in Shelby County

Direct sow Napa Cabbage outdoors after March 21 in Shelby 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 Shelby County, TN?

Shelby County is in Zone 8a with an average last frost of March 21. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Shelby County, TN?

Shelby County, Tennessee is in USDA Hardiness Zone 8a. The average last spring frost is March 21 and first fall frost is November 5.

🌱

Your Shelby County Garden Planner — Free

A 24-page printable planner built for Shelby County (Zone 8a). 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 Shelby County, TN. 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.