When to Plant Black-Eyed Susans in Illinois
Cheerful golden blooms that attract butterflies and tolerate drought. A backbone of the low-maintenance perennial garden.
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 |
Black-Eyed Susans 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 Black-Eyed Susans in Illinois
Black-Eyed Susans in Illinois's Climate
Black-eyed Susans grow wild along roadsides throughout the moderate zone — proof they need no help in your conditions. Goldsturm is the standard garden variety. Full sun produces the most flowers. Nearly maintenance-free once established.
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. Black-Eyed Susans can handle frost well, which is an advantage in Illinois's climate. You can push planting dates earlier in spring and extend into fall.
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 black-eyed susans — but black-eyed susans handle frost well, so the timing difference is less critical.
Growing Tips
Leave seed heads standing through winter for birds and visual interest. Self-seeds freely — deadhead if you don't want more.
Companion Planting
Plant black-eyed susans alongside these companions for better growth:
The Bottom Line
Last reviewed: March 29, 2026