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When to plant Napa Cabbage in Viola, DE

The best window to plant Napa Cabbage in Viola, is March 19–April 9, when soil warms to 50°F. Last frost typically hits April 2; first frost November 4. A second sowing from August 26 to September 9 extends the harvest into fall.

When to Plant Napa Cabbage in Viola, DE

Kent County, Delaware Zone 7b June

Top priorities for Kent County, Delaware gardeners in June

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

Avg. last frost April 2
Avg. first frost November 4
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 14.7 hrs

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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.

Viola, Delaware is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is November 4, giving you a growing season of approximately 216 days.

At an elevation of 128 feet, Kent County receives approximately 47.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Napa Cabbage during the growing season.

Viola, DE (Zone 7b) Long season
216 days
Last Spring Frost April 2
216 growing days
First Fall Frost November 4

Viola Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Napa Cabbage Planting Risk Windows

Early Start (70% safe) ✓ Fits season (125 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: May 23 – Jun 27
Recommended (50%) ✓ Fits season (125 days to spare)
Start indoors: Feb 26 Transplant: Apr 2 🍅 Harvest: May 28 – Jul 2
Safe Start (90%) ✓ Fits season (120 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jun 13 – Jul 18

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 Viola

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

Soil pH

Your soil pH (5.8–6.8) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). 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 216-day season

Sow every 6.3 weeks. Last sowing by Aug 21 to harvest before frost.

For a dedicated fall crop, sow by Aug 26.

Napa Cabbage Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,093 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" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 6.5" 4" 2.5" 💧 Light watering
May 6.5" 4.6" 1.9" 💧 Light watering
Jun 6.5" 3.9" 2.6" 💧 Light watering
Jul 6.5" 5.6" 0.9" 💧 Light watering
Aug 6.5" 4.9" 1.6" 💧 Light watering
Sep 6.5" 3.7" 2.8" 💧 Light watering
Oct 6.5" 4" 2.5" 💧 Light watering
Nov 6.5" 3.5" 3" 💧 Light watering
Dec 3.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Kent 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 ~1,040 GDD — county provides 3,456 GDD Excellent fit

Napa Cabbage Planting Timeline — Viola, DE

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 – Mar 12
Transplant Outdoors April 2 Apr 2 – Apr 16
Direct Sow March 19 Mar 19 – Apr 9
Harvest May 28 May 28 – Jul 2
Fall Sowing August 26 Aug 26 – Sep 9

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 · 1-2 times/week

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

216 days in Kent County

Growing Tips for Napa Cabbage in Viola

Direct sow Napa Cabbage outdoors after April 02 in Kent 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 →

When should I plant Napa Cabbage in Viola, DE?

In Viola, DE, plant Napa Cabbage after the last frost (around April 2) and before the first frost (around November 4). Best results when soil holds above 50°F.

What growing zone is Viola, DE for Napa Cabbage?

Viola sits in USDA Zone 7b. Napa Cabbage grows reliably in zones 2a through 11b, so it's a good fit here.

Can Napa Cabbage grow in Viola's climate?

Yes — Napa Cabbage grows well in Viola's temperate climate. Viola averages a 216-day frost-free season, with last frost around April 2 and first frost around November 4.

🌱

Your Kent County Garden Planner — Free

A 22-page printable planner built for Kent County (Zone 7b). 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 Kent County, DE. Local conditions may vary. Last updated: June 2026.