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When to plant Eggplant in New Castle County, DE

Spring Eggplant in New Castle County goes in April 13–May 4, once nighttime temps stop dipping near freezing.

When to Plant Eggplant in New Castle County, DE

Eggplant
New Castle County, Delaware Zone 7b July

This month in New Castle County, Delaware

Welcome to July in Zone 7b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 6
Avg. first frost October 31
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
  1. Bring in the eggplant

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Looking ahead to August
  • First harvests: eggplant

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Eggplant is a heat-loving solanaceous crop that produces glossy fruits in purple, white, or striped varieties. It requires long, warm growing seasons for best production.

New Castle County, Delaware is in USDA Zone 7b. 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 89°F, providing good warmth for Eggplant during the growing season.

New Castle County, DE (Zone 7b) 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

Eggplant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Jan 24 Transplant: Apr 11 🍅 Harvest: Jun 20 – Aug 22
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Feb 2 Transplant: Apr 20 🍅 Harvest: Jun 29 – Aug 31
Safe Start (90%) ✓ Fits season (49 days to spare)
Start indoors: Feb 26 Transplant: May 14 🍅 Harvest: Jul 23 – Sep 24

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 Eggplant's growing requirements.

Soil pH

Your soil pH (5.2–7.1) overlaps with Eggplant's range (5.5–7.0), though not a perfect match.

Soil Texture

The silt loam soil in New Castle County is excellent for Eggplant — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Eggplant

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Eggplant

3
successive plantings in your 208-day season

Sow every 7.4 weeks. Last sowing by Aug 07 to harvest before frost.

Eggplant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 612 gal / 100 sq ft

Monthly Watering Guide for Eggplant

Eggplant needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Eggplant Needs Rainfall You Supplement Action
Jan 2.4" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 3.4" 0" ❄️ Dormant
Apr 4.8" 3.2" 1.6" 💧 Light watering
May 4.8" 3.3" 1.5" 💧 Light watering
Jun 4.8" 3.3" 1.5" 💧 Light watering
Jul 4.8" 4.1" 0.7" 💧 Light watering
Aug 4.8" 3.2" 1.6" 💧 Light watering
Sep 4.8" 3.1" 1.7" 💧 Light watering
Oct 4.8" 3.2" 1.6" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 2.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in New Castle County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Eggplant 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.

Eggplant needs ~1,256 GDD — county provides 3,484 GDD Excellent fit

Eggplant Planting Timeline — New Castle County, DE

Eggplant Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 13 Apr 13 – May 4
Harvest June 29 Jun 29 – Aug 31

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 1-2 times/week

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

208 days in New Castle County

Growing Tips for Eggplant in New Castle County

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

Common pests for Eggplant in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8-10 weeks before last frost. Transplant only after nighttime temperatures stay above 55F. Mulch to retain moisture and warmth around roots.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Kohlrabi

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

New Castle County is in Zone 7b with an average last frost of April 6. Plan your Eggplant planting based on this frost date — see the calendar above for exact timing.

What planting zone is New Castle County, DE?

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

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

In New Castle County, DE, plant Eggplant after the last frost (around April 6) and before the first frost (around October 31). Best results when soil holds above 50°F.

What growing zone is New Castle County, DE for Eggplant?

New Castle County sits in USDA Zone 7b. Eggplant grows reliably in zones 5a through 11b, so it's a good fit here.

Can Eggplant grow in New Castle County's climate?

Yes — Eggplant grows well in New Castle County's temperate climate. New Castle County averages a 208-day frost-free season, with last frost around April 6 and first frost around October 31.

🌱

Your New Castle County Garden Planner — Free

A 22-page printable planner built for New Castle 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 New Castle County, DE. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.