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When to Plant Cabbage in New Castle County, DE

Cabbage is a versatile cool-season crop that forms dense, leafy heads in green, red, or savoy varieties. It is a staple for coleslaw, sauerkraut, and many global cuisines.

New Castle County, Delaware is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is October 31, giving you a growing season of approximately 208 days.

At an elevation of 415 feet, New Castle County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Cabbage during the growing season.

New Castle County, DE (Zone 7a) Long season
208 days
Last Spring Frost April 6
208 growing days
First Fall Frost October 31

New Castle County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (92 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: May 30 – Jul 25
Recommended (50%) ✓ Fits season (89 days to spare)
Start indoors: Mar 2 Transplant: Apr 6 🍅 Harvest: Jun 8 – Aug 3
Safe Start (90%) ✓ Fits season (77 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jul 2 – Aug 27

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 New Castle County

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

Soil pH

Your soil pH (5.2โ€“7.1) overlaps with Cabbage's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Cabbage.

How to Plant 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 Cabbage

4
successive plantings in your 208-day season

Sow every 6.9 weeks. Last sowing by Jul 23 to harvest before frost.

For a dedicated fall crop, sow by Aug 22.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 242 gal / 100 sq ft

Monthly Watering Guide for Cabbage

Cabbage needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Cabbage Needs Rainfall You Supplement Action
Jan โ€” 2.4" 0" โ„๏ธ Dormant
Feb โ€” 2.7" 0" โ„๏ธ Dormant
Mar โ€” 3.4" 0" โ„๏ธ Dormant
Apr 3.9" 3.2" 0.7" ๐Ÿ’ง Light watering
May 3.9" 3.3" 0.6" ๐Ÿ’ง Light watering
Jun 3.9" 3.3" 0.6" ๐Ÿ’ง Light watering
Jul 3.9" 4.1" 0" โœ… Rainfall sufficient
Aug 3.9" 3.2" 0.7" ๐Ÿ’ง Light watering
Sep 3.9" 3.1" 0.8" ๐Ÿ’ง Light watering
Oct 3.9" 3.2" 0.7" ๐Ÿ’ง Light watering
Nov โ€” 3.4" 0" โ„๏ธ Dormant
Dec โ€” 2.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in New Castle County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

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.

Cabbage needs ~1,340 GDD — county provides 3,484 GDD Excellent fit

Cabbage Planting Timeline โ€” New Castle County, DE

Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 โ€“ Mar 16
Transplant Outdoors April 6 Apr 6 โ€“ Apr 20
Direct Sow March 23 Mar 23 โ€“ Apr 13
Harvest June 8 Jun 8 โ€“ Aug 3
Fall Sowing August 22 Aug 22 โ€“ Sep 5

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.9"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

208 days in New Castle County

Growing Tips for Cabbage in New Castle County

Direct sow Cabbage outdoors after April 06 in New Castle County when soil has warmed and frost danger has passed.

Common pests for Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 4-6 weeks before last frost. Space plants 18-24 inches apart. Keep soil evenly moist to prevent heads from splitting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cabbage in New Castle County, DE?

New Castle County is in Zone 7a with an average last frost of April 6. Plan your Cabbage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is New Castle County, DE?

New Castle County, Delaware is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is October 31.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help New Castle County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for New Castle County, DE. Local conditions may vary. Last updated: April 2026.