When to plant garlic in Illinois
Illinois spans USDA zones 5a–7a, so the right time to plant garlic shifts by weeks across the state. The window to plant for fall/overwintering runs from about September 13 in McHenry to October 8 in Chicago — below are local dates for 226 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Fall-plant |
|---|---|---|---|---|
| Chicago | 6a | April 10 | November 5 | October 8 – October 22 |
| Aurora | 5b | April 19 | October 23 | September 25 – October 9 |
| Naperville | 5b | April 28 | October 16 | September 18 – October 2 |
| Joliet | 5b | April 19 | October 25 | September 27 – October 11 |
| Rockford | 5b | April 24 | October 17 | September 19 – October 3 |
| Elgin | 5b | April 26 | October 18 | September 20 – October 4 |
| Springfield | 6a | April 15 | October 22 | September 24 – October 8 |
| Peoria | 6a | April 16 | October 23 | September 25 – October 9 |
Garlic in Illinois: FAQ
When can I plant garlic in Illinois?
Across Illinois, the time to fall-plant garlic spans roughly September 13 in McHenry to October 8 in Chicago, each following that city's local frost dates.
Does the garlic planting date vary across Illinois?
Yes. Illinois publishes 226 cities with their own frost dates, so the right garlic planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.
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