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When to Plant Napa Cabbage in Hardin County, KY

Hardin County, Kentucky Zone 6b April

Your April planting checklist for Hardin County, Kentucky

A quick April briefing for Hardin County, Kentucky gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 4
Avg. first frost November 1
Soil temp (4") 52°F
Watering Low
Pest pressure Low
Daylight 13 hrs
  1. Move napa cabbage into the garden

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

Coming up in May — start thinking about
  • Starting indoors: napa cabbage
  • 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.

Hardin County, Kentucky is in USDA Zone 6b. The average last spring frost is April 4 and the first fall frost is November 1, giving you a growing season of approximately 211 days.

At an elevation of 1,464 feet, Hardin County receives approximately 48.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Napa Cabbage during the growing season.

Hardin County, KY (Zone 6b) Long season
211 days
Last Spring Frost April 4
211 growing days
First Fall Frost November 1

Hardin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (120 days to spare)
Start indoors: Feb 22 Transplant: Mar 29 🍅 Harvest: May 24 – Jun 28
Recommended (50%) ✓ Fits season (120 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: May 30 – Jul 4
Safe Start (90%) ✓ Fits season (114 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 17 – Jul 22

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 Hardin County

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

Soil pH

Your soil pH (5.7–6.8) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Hardin 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

4
successive plantings in your 211-day season

Sow every 6.3 weeks. Last sowing by Aug 18 to harvest before frost.

For a dedicated fall crop, sow by Aug 23.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 177 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 4.5" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 6.5" 4.2" 2.3" 💧 Light watering
May 6.5" 3.4" 3.1" 💧 Light watering
Jun 6.5" 4.2" 2.3" 💧 Light watering
Jul 6.5" 5.6" 0.9" 💧 Light watering
Aug 6.5" 5" 1.5" 💧 Light watering
Sep 6.5" 3.5" 3" 💧 Light watering
Oct 6.5" 2.8" 3.7" 🚿 Regular watering
Nov 6.5" 3.9" 2.6" 💧 Light watering
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Hardin 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 ~991 GDD — county provides 3,217 GDD Excellent fit

Napa Cabbage Planting Timeline — Hardin County, KY

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors April 4 Apr 4 – Apr 18
Direct Sow March 21 Mar 21 – Apr 11
Harvest May 30 May 30 – Jul 4
Fall Sowing August 23 Aug 23 – Sep 6

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

211 days in Hardin County

Growing Tips for Napa Cabbage in Hardin County

Direct sow Napa Cabbage outdoors after April 04 in Hardin 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 Hardin County, KY?

Hardin County is in Zone 6b with an average last frost of April 4. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hardin County, KY?

Hardin County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 4 and first fall frost is November 1.

🌱

Your Hardin County Garden Planner — Free

A 24-page printable planner built for Hardin County (Zone 6b). 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 Hardin County, KY. 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.