When to Plant Eggplant in Illinois
Beautiful purple fruits that love heat even more than tomatoes. Start early indoors for best results.
The Short Answer
Illinois Frost Dates
Your planting dates depend on which part of Illinois you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern Illinois (Chicago) | 5a, 5b | Apr 25 - May 10 | Oct 1 - Oct 15 |
| Central Illinois | 5b, 6a | Apr 15 - May 1 | Oct 5 - Oct 20 |
| Southern Illinois | 6b, 7a | Apr 1 - Apr 15 | Oct 15 - Nov 1 |
Eggplant Planting Schedule for Illinois
Northern Illinois (Chicago) (Zones 5a, 5b)
Average last frost: Apr 25 - May 10 · Average first frost: Oct 1 - Oct 15
Central Illinois (Zones 5b, 6a)
Average last frost: Apr 15 - May 1 · Average first frost: Oct 5 - Oct 20
Southern Illinois (Zones 6b, 7a)
Average last frost: Apr 1 - Apr 15 · Average first frost: Oct 15 - Nov 1
Growing Eggplant in Illinois
Eggplant in Illinois's Climate
Eggplant grows well in your warmer microclimates with proper timing. Start indoors 8-10 weeks before last frost. Don't transplant until nighttime temperatures consistently exceed 60°F. Asian varieties produce more reliably than Italian globe types in your climate. Full sun in the warmest garden spot.
Soil Considerations for Illinois
Rich prairie soils — some of the most fertile in the country. Heavy clay in many areas. Well-suited for most vegetables. Make sure soil has warmed to at least 70°F before planting eggplant outside.
Illinois Climate & Growing Season
Continental climate with four seasons. Hot, humid summers. Cold winters. Good growing season length in central and southern regions. Eggplant cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
Growing season length varies across Illinois: Northern Illinois (Chicago) (5a, 5b) has a last frost around Apr 25 - May 10, while Southern Illinois (6b, 7a) sees frost end around Apr 1 - Apr 15. This difference matters for eggplant — transplant timing shifts by several weeks across the state.
Growing Tips
Harvest when skin is glossy and firm. Dull skin means overripe and seedy. Use row covers if nights are cool.
Companion Planting
Plant eggplant alongside these companions for better growth:
Keep eggplant away from:
The Bottom Line
Last reviewed: March 29, 2026