When to plant potato in Illinois
Illinois spans USDA zones 5a–7a, so the right time to plant potato shifts by weeks across the state. The window to sow seed directly outdoors runs from about March 7 in Granite City to April 3 in McHenry — below are local dates for 226 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Direct sow |
|---|---|---|---|---|
| Chicago | 6a | April 10 | November 5 | March 13 – March 27 |
| Aurora | 5b | April 19 | October 23 | March 22 – April 5 |
| Naperville | 5b | April 28 | October 16 | March 31 – April 14 |
| Joliet | 5b | April 19 | October 25 | March 22 – April 5 |
| Rockford | 5b | April 24 | October 17 | March 27 – April 10 |
| Elgin | 5b | April 26 | October 18 | March 29 – April 12 |
| Springfield | 6a | April 15 | October 22 | March 18 – April 1 |
| Peoria | 6a | April 16 | October 23 | March 19 – April 2 |
Potato in Illinois: FAQ
When can I plant potato in Illinois?
Across Illinois, the time to direct-sow potato spans roughly March 7 in Granite City to April 3 in McHenry, each following that city's local frost dates.
Does the potato planting date vary across Illinois?
Yes. Illinois publishes 226 cities with their own frost dates, so the right potato planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.
How long does potato take to grow in Illinois?
Potato takes about 70–120 days to reach harvest once planted — check that this fits inside your city's frost-free season on its place page.
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