When to Plant Cilantro in Illinois
You either love it or your genetics say no. For the cilantro lovers, it's an essential herb that bolts fast in heat.
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 |
Cilantro 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 Cilantro in Illinois
Cilantro in Illinois's Climate
Cilantro thrives in your cool springs and falls but bolts rapidly once temperatures exceed 80°F. Succession plant every 2-3 weeks during the cool windows. Let some plants bolt to produce coriander seeds (a spice in their own right) and self-seed for volunteer plants next season.
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.
Illinois Climate & Growing Season
Continental climate with four seasons. Hot, humid summers. Cold winters. Good growing season length in central and southern regions.
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 cilantro — adjust your planting dates to match your specific region.
Growing Tips
Bolts quickly in heat — succession plant every 3 weeks and grow in partial shade during summer. Let some bolt for coriander seeds.
Companion Planting
Plant cilantro alongside these companions for better growth:
Keep cilantro away from:
The Bottom Line
Last reviewed: March 29, 2026