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When to Plant Napa Cabbage in Warren County, NJ

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.

Warren County, New Jersey is in USDA Zone 6a. The average last spring frost is April 16 and the first fall frost is October 27, giving you a growing season of approximately 194 days.

At an elevation of 369 feet, Warren County receives approximately 48.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Napa Cabbage during the growing season.

Warren County, NJ (Zone 6a) Moderate season
194 days
Last Spring Frost April 16
194 growing days
First Fall Frost October 27

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (103 days to spare)
Start indoors: Mar 2 Transplant: Apr 6 🍅 Harvest: Jun 1 – Jul 6
Recommended (50%) ✓ Fits season (103 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 11 – Jul 16
Safe Start (90%) ✓ Fits season (99 days to spare)
Start indoors: Apr 4 Transplant: May 9 🍅 Harvest: Jul 4 – Aug 8

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 Warren County

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

Soil pH

Your soil pH (5.2โ€“6.4) is more acidic than Napa Cabbage prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Warren County is excellent for Napa Cabbage โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.3%). 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 194-day season

Sow every 6.3 weeks. Last sowing by Aug 13 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 788 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 โ€” 4" 0" โ„๏ธ Dormant
Feb โ€” 3" 0" โ„๏ธ Dormant
Mar โ€” 4.5" 0" โ„๏ธ Dormant
Apr 6.5" 3.6" 2.9" ๐Ÿ’ง Light watering
May 6.5" 3.9" 2.6" ๐Ÿ’ง Light watering
Jun 6.5" 4.2" 2.3" ๐Ÿ’ง Light watering
Jul 6.5" 4.4" 2.1" ๐Ÿ’ง Light watering
Aug 6.5" 4.3" 2.2" ๐Ÿ’ง Light watering
Sep 6.5" 4.7" 1.8" ๐Ÿ’ง Light watering
Oct 6.5" 4.3" 2.2" ๐Ÿ’ง Light watering
Nov โ€” 3.4" 0" โ„๏ธ Dormant
Dec โ€” 4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Warren County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 2,813 GDD Excellent fit

Napa Cabbage Planting Timeline โ€” Warren County, NJ

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 โ€“ Mar 26
Transplant Outdoors April 16 Apr 16 โ€“ Apr 30
Direct Sow April 2 Apr 2 โ€“ Apr 23
Harvest June 11 Jun 11 โ€“ Jul 16
Fall Sowing August 18 Aug 18 โ€“ Sep 1

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1.5"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

55โ€“75 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

194 days in Warren County

Growing Tips for Napa Cabbage in Warren County

Direct sow Napa Cabbage outdoors after April 16 in Warren 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 Warren County, NJ?

Warren County is in Zone 6a with an average last frost of April 16. Plan your Napa Cabbage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Warren County, NJ?

Warren County, New Jersey is in USDA Hardiness Zone 6a. The average last spring frost is April 16 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Warren County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

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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 Warren County, NJ. Local conditions may vary. Last updated: April 2026.