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When to plant Eggplant in Warren County, IL

In Warren County, plant Eggplant in spring between April 20 and May 11, once soil temps hold above 50°F. Warren County's last frost averages April 13, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 65–85 days before the first frost on October 21.

When to Plant Eggplant in Warren County, IL

Eggplant

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.

Warren County, Illinois is in USDA Zone 5b. 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 801 feet, Warren County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Eggplant during the growing season.

Warren County, IL (Zone 5b) Moderate season
191 days
Last Spring Frost April 13
191 growing days
First Fall Frost October 21

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

How Much Eggplant to Grow

4-6 lbs
Average yield per plant
2
Plants per person
4 sq ft
Space per person

For a family of 4, plant approximately 8 eggplant plants in about 16 sq ft. In Warren County's 191-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Monthly Watering Guide for Eggplant

Eggplant needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Eggplant Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 2.8" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Eggplant Planting Timeline — Warren 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

Moderate — regular watering

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

191 days in Warren County

Growing Tips for Warren County

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 Warren County, IL?

Warren County is in Zone 5b 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 Warren County, IL?

Warren County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 13 and first fall frost is October 21.

When should I plant Eggplant in Warren County, IL?

In Warren County, IL, plant Eggplant after the last frost (around April 13) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Warren County, IL for Eggplant?

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

Can Eggplant grow in Warren County's climate?

Yes — Eggplant grows well in Warren County's temperate climate. Warren County averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.

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Your Warren County Garden Planner — Free

A 22-page printable planner built for Warren County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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