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When to Plant Napa Cabbage in Prince William County, VA

Prince William County, Virginia Zone 7a May

What to do in May

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

Avg. last frost April 13
Avg. first frost October 26
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 14.1 hrs
  1. Fire up the seed-starting tray: napa cabbage

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

Coming up in June — start thinking about
  • 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.

Prince William County, Virginia is in USDA Zone 7a. The average last spring frost is April 13 and the first fall frost is October 26, giving you a growing season of approximately 196 days.

At an elevation of 372 feet, Prince William County receives approximately 46.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Napa Cabbage during the growing season.

Prince William County, VA (Zone 7a) Moderate season
196 days
Last Spring Frost April 13
196 growing days
First Fall Frost October 26

Prince William County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (109 days to spare)
Start indoors: Feb 25 Transplant: Apr 1 🍅 Harvest: May 27 – Jul 1
Recommended (50%) ✓ Fits season (105 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jun 8 – Jul 13
Safe Start (90%) ✓ Fits season (108 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 Prince William County

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

Soil pH

Your soil pH (5.8–7.0) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

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 196-day season

Sow every 6.3 weeks. Last sowing by Aug 12 to harvest before frost.

For a dedicated fall crop, sow by Aug 17.

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 890 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 4.5" 0" ❄️ Dormant
Feb 4.2" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 6.5" 3.5" 3" 💧 Light watering
May 6.5" 4.1" 2.4" 💧 Light watering
Jun 6.5" 4.1" 2.4" 💧 Light watering
Jul 6.5" 4.6" 1.9" 💧 Light watering
Aug 6.5" 4.1" 2.4" 💧 Light watering
Sep 6.5" 3.1" 3.4" 🚿 Regular watering
Oct 6.5" 2.8" 3.7" 🚿 Regular watering
Nov 3.2" 0" ❄️ Dormant
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Prince William 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 3,283 GDD Excellent fit

Napa Cabbage Planting Timeline — Prince William County, VA

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow March 30 Mar 30 – Apr 20
Harvest June 8 Jun 8 – Jul 13
Fall Sowing August 17 Aug 17 – Aug 31

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May
June Harvest
July Harvest
August Fall Sowing
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 7a

📆 Growing Season

196 days in Prince William County

Growing Tips for Napa Cabbage in Prince William County

Direct sow Napa Cabbage outdoors after April 13 in Prince William 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 Prince William County, VA?

Prince William County is in Zone 7a with an average last frost of April 13. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Prince William County, VA?

Prince William County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is April 13 and first fall frost is October 26.

🌱

Your Prince William County Garden Planner — Free

A 24-page printable planner built for Prince William 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.

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 Prince William County, VA. 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.