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When to Plant Eggplant in Monmouth County, NJ

Monmouth County, New Jersey Zone 7b May

May in the garden — Monmouth County, New Jersey

Each item below is timed to Monmouth County, New Jersey's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 29
Avg. first frost November 12
Soil temp (4") 68°F
Watering Moderate
Pest pressure Moderate
Daylight 14.2 hrs
  1. Sow eggplant in trays indoors

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

Looking ahead to June
  • 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.

Monmouth County, New Jersey is in USDA Zone 7b. The average last spring frost is March 29 and the first fall frost is November 12, giving you a growing season of approximately 228 days.

At an elevation of 280 feet, Monmouth County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Eggplant during the growing season.

Monmouth County, NJ (Zone 7b) Long season
228 days
Last Spring Frost March 29
228 growing days
First Fall Frost November 12

Monmouth County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Start indoors: Jan 21 Transplant: Apr 8 🍅 Harvest: Jun 17 – Aug 19
Recommended (50%) ✓ Fits season (81 days to spare)
Start indoors: Jan 25 Transplant: Apr 12 🍅 Harvest: Jun 21 – Aug 23
Safe Start (90%) ✓ Fits season (90 days to spare)
Start indoors: Feb 5 Transplant: Apr 23 🍅 Harvest: Jul 2 – Sep 3

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 Monmouth County

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

Soil pH

Your soil pH (5.0–6.8) overlaps with Eggplant's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Eggplant.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Eggplant.

How to Plant Eggplant

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

Succession Planting Eggplant

4
successive plantings in your 228-day season

Sow every 7.4 weeks. Last sowing by Aug 19 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 105 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 2.7" 0" ❄️ Dormant
Feb 2.5" 0" ❄️ Dormant
Mar 4.8" 3.6" 1.2" 💧 Light watering
Apr 4.8" 3.8" 1" 💧 Light watering
May 4.8" 3.6" 1.2" 💧 Light watering
Jun 4.8" 3.2" 1.6" 💧 Light watering
Jul 4.8" 4" 0.8" 💧 Light watering
Aug 4.8" 3.6" 1.2" 💧 Light watering
Sep 4.8" 3.2" 1.6" 💧 Light watering
Oct 4.8" 3.2" 1.6" 💧 Light watering
Nov 4.8" 2.6" 2.2" 💧 Light watering
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Monmouth 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 3,819 GDD Excellent fit

Eggplant Planting Timeline — Monmouth County, NJ

Eggplant Planting Calendar

Activity When Date Range
Start Indoors January 25 Jan 25 – Feb 8
Transplant Outdoors April 12 Apr 12 – Apr 26
Direct Sow April 5 Apr 5 – Apr 26
Harvest June 21 Jun 21 – Aug 23

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · Only during dry spells

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

228 days in Monmouth County

Growing Tips for Eggplant in Monmouth County

Direct sow Eggplant outdoors after March 29 in Monmouth 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 Monmouth County, NJ?

Monmouth County is in Zone 7b with an average last frost of March 29. Plan your Eggplant planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monmouth County, NJ?

Monmouth County, New Jersey is in USDA Hardiness Zone 7b. The average last spring frost is March 29 and first fall frost is November 12.

🌱

Your Monmouth County Garden Planner — Free

A 24-page printable planner built for Monmouth 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 Monmouth County, NJ. 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.