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When to Plant Eggplant in McLean County, IL

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.

McLean County, Illinois is in USDA Zone 5a. The average last spring frost is April 18 and the first fall frost is October 18, giving you a growing season of approximately 183 days.

At an elevation of 1,024 feet, McLean County receives approximately 31.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Eggplant during the growing season.

McLean County, IL (Zone 5a) Moderate season
183 days
Last Spring Frost April 18
183 growing days
First Fall Frost October 18

McLean County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (33 days to spare)
Start indoors: Feb 3 Transplant: Apr 28 🍅 Harvest: Jul 7 – Sep 8
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Feb 7 Transplant: May 2 🍅 Harvest: Jul 11 – Sep 12
Safe Start (90%) ✓ Fits season (36 days to spare)
Start indoors: Feb 21 Transplant: May 16 🍅 Harvest: Jul 25 – Sep 26

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 McLean County

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

Soil pH

Your soil pH (6.0โ€“7.0) is within Eggplant's preferred range (5.5โ€“7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) โ€” Eggplant will thrive.

How to Plant Eggplant

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

Succession Planting Eggplant

3
successive plantings in your 183-day season

Sow every 7.4 weeks. Last sowing by Jul 25 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 599 gal / 100 sq ft
Eggplant needs ~1,088 GDD — county provides 2,653 GDD Excellent fit

Eggplant Planting Timeline โ€” McLean County, IL

Eggplant Planting Calendar

Activity When Date Range
Start Indoors February 7 Feb 7 โ€“ Feb 21
Transplant Outdoors May 2 May 2 โ€“ May 16
Direct Sow April 25 Apr 25 โ€“ May 16
Harvest July 11 Jul 11 โ€“ Sep 12

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

65โ€“85 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

183 days in McLean County

Growing Tips for Eggplant in McLean County

Direct sow Eggplant outdoors after April 18 in McLean 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Eggplant in McLean County, IL?

McLean County is in Zone 5a with an average last frost of April 18. Plan your Eggplant planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is McLean County, IL?

McLean County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 18 and first fall frost is October 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help McLean County gardeners in Zone 5a 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 McLean County, IL. Local conditions may vary. Last updated: April 2026.