When to Plant Eggplant in Coles 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.
Coles County, Illinois is in USDA Zone 5b. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.
At an elevation of 779 feet, Coles County receives approximately 34.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Eggplant during the growing season.
Coles County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.2
Drainage
Well Drained
How Much Eggplant to Grow
For a family of 4, plant approximately 8 eggplant plants in about 16 sq ft. In Coles County's 186-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 | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Aug | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Sep | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 1.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Coles County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Eggplant Planting Timeline — Coles County, IL
Eggplant Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 3 | Feb 3 – Feb 17 |
| Transplant Outdoors | April 28 | Apr 28 – May 12 |
| Direct Sow | April 21 | Apr 21 – May 12 |
| Harvest | July 7 | Jul 7 – Sep 8 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
186 days in Coles County
Growing Tips for Coles 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
Check more plant combinations with our Companion Planting Checker →
Eggplant in Other Locations
Frequently Asked Questions
When should I plant Eggplant in Coles County, IL?
Coles County is in Zone 5b with an average last frost of April 14. Plan your Eggplant planting based on this frost date — see the calendar above for exact timing.
What planting zone is Coles County, IL?
Coles County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 14 and first fall frost is October 17.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Coles County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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