When to plant onion in Indiana
Indiana spans USDA zones 5b–7a, so the right time to plant onion shifts by weeks across the state. The window to transplant seedlings outdoors runs from about March 1 in Evansville to April 4 in Auburn — below are local dates for 86 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Transplant out |
|---|---|---|---|---|
| Indianapolis | 6b | April 20 | October 21 | March 23 – April 6 |
| Fort Wayne | 6a | April 24 | October 21 | March 27 – April 10 |
| Evansville | 7a | March 29 | November 10 | March 1 – March 15 |
| South Bend | 6a | April 23 | October 23 | March 26 – April 9 |
| Fishers | 6a | April 21 | October 21 | March 24 – April 7 |
| Carmel | 6a | April 21 | October 21 | March 24 – April 7 |
| Bloomington | 6b | April 15 | October 26 | March 18 – April 1 |
| Hammond | 6a | April 23 | October 20 | March 26 – April 9 |
Onion in Indiana: FAQ
When can I plant onion in Indiana?
Across Indiana, the time to transplant onion spans roughly March 1 in Evansville to April 4 in Auburn, each following that city's local frost dates.
Does the onion planting date vary across Indiana?
Yes. Indiana publishes 86 cities with their own frost dates, so the right onion 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 onion take to grow in Indiana?
Onion takes about 90–110 days to reach harvest once planted — check that this fits inside your city's frost-free season on its place page.
Never miss a window in your area
An email when it’s time to start seeds, transplant, and sow — timed to your frost dates. Double opt-in, one-click unsubscribe, no spam.