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When to Plant Eggplant in Greene County, IL

Greene County, Illinois Zone 6a May

Your May game plan for Greene County, Illinois

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Avg. last frost April 13
Avg. first frost October 21
Soil temp (4") 57°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
June will be here before you know it — start on
  • Starting indoors: 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.

Greene County, Illinois is in USDA Zone 6a. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.

At an elevation of 1,248 feet, Greene County receives approximately 37 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Eggplant during the growing season.

Greene County, IL (Zone 6a) Moderate season
191 days
Last Spring Frost April 13
191 growing days
First Fall Frost October 21

Greene County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (43 days to spare)
Start indoors: Jan 27 Transplant: Apr 21 🍅 Harvest: Jun 30 – Sep 1
Recommended (50%) ✓ Fits season (44 days to spare)
Start indoors: Feb 2 Transplant: Apr 27 🍅 Harvest: Jul 6 – Sep 7
Safe Start (90%) ✓ Fits season (43 days to spare)
Start indoors: Feb 14 Transplant: May 9 🍅 Harvest: Jul 18 – Sep 19

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 Greene County

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

Soil pH

Your soil pH (6.1–6.7) is within Eggplant's preferred range (5.5–7.0).

Soil Texture

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

Drainage

Drainage is adequate for Eggplant.

Organic Matter

Organic matter is excellent (4.5%) — Eggplant will thrive.

How to Plant Eggplant

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

Succession Planting Eggplant

3
successive plantings in your 191-day season

Sow every 7.4 weeks. Last sowing by Jul 28 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.8″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,257 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.6" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.8" 3.2" 1.6" 💧 Light watering
May 4.8" 3.9" 0.9" 💧 Light watering
Jun 4.8" 4.5" 0.3" 💧 Light watering
Jul 4.8" 3.9" 0.9" 💧 Light watering
Aug 4.8" 4.4" 0.4" 💧 Light watering
Sep 4.8" 3.3" 1.5" 💧 Light watering
Oct 4.8" 3" 1.8" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Greene 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 ~1,088 GDD — county provides 2,769 GDD Excellent fit

Eggplant Planting Timeline — Greene County, IL

Eggplant Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors April 27 Apr 27 – May 11
Direct Sow April 20 Apr 20 – May 11
Harvest July 6 Jul 6 – Sep 7

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
July Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 2-3 times/week

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

191 days in Greene County

Growing Tips for Eggplant in Greene County

Direct sow Eggplant outdoors after April 13 in Greene 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 Greene County, IL?

Greene County is in Zone 6a with an average last frost of April 13. Plan your Eggplant planting based on this frost date — see the calendar above for exact timing.

What planting zone is Greene County, IL?

Greene County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 13 and first fall frost is October 21.

🌱

Your Greene County Garden Planner — Free

A 24-page printable planner built for Greene County (Zone 6a). 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 Greene County, IL. 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.