When to plant broccoli in Illinois
Illinois spans USDA zones 5a–7a, so the right time to plant broccoli shifts by weeks across the state. The window to transplant seedlings outdoors runs from about March 14 in Granite City to April 10 in McHenry — below are local dates for 226 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Transplant out |
|---|---|---|---|---|
| Chicago | 6a | April 10 | November 5 | March 20 – April 3 |
| Aurora | 5b | April 19 | October 23 | March 29 – April 12 |
| Naperville | 5b | April 28 | October 16 | April 7 – April 21 |
| Joliet | 5b | April 19 | October 25 | March 29 – April 12 |
| Rockford | 5b | April 24 | October 17 | April 3 – April 17 |
| Elgin | 5b | April 26 | October 18 | April 5 – April 19 |
| Springfield | 6a | April 15 | October 22 | March 25 – April 8 |
| Peoria | 6a | April 16 | October 23 | March 26 – April 9 |
Broccoli in Illinois: FAQ
When can I plant broccoli in Illinois?
Across Illinois, the time to transplant broccoli spans roughly March 14 in Granite City to April 10 in McHenry, each following that city's local frost dates.
Does the broccoli planting date vary across Illinois?
Yes. Illinois publishes 226 cities with their own frost dates, so the right broccoli 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 broccoli take to grow in Illinois?
Broccoli takes about 55–80 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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