When to plant onion in Alabama
Alabama spans USDA zones 7b–9a, so the right time to plant onion shifts by weeks across the state. The window to transplant seedlings outdoors runs from about January 24 in Mobile to March 9 in Jacksonville — below are local dates for 70 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Transplant out |
|---|---|---|---|---|
| Huntsville | 8a | March 24 | November 8 | February 24 – March 10 |
| Mobile | 9a | February 21 | December 6 | January 24 – February 7 |
| Birmingham | 8a | March 21 | November 11 | February 21 – March 7 |
| Montgomery | 8b | March 4 | November 18 | February 4 – February 18 |
| Tuscaloosa | 8b | March 18 | November 10 | February 18 – March 4 |
| Hoover | 8a | March 19 | November 8 | February 19 – March 5 |
| Auburn | 8b | March 13 | November 17 | February 13 – February 27 |
| Dothan | 9a | March 1 | November 24 | February 1 – February 15 |
Onion in Alabama: FAQ
When can I plant onion in Alabama?
Across Alabama, the time to transplant onion spans roughly January 24 in Mobile to March 9 in Jacksonville, each following that city's local frost dates.
Does the onion planting date vary across Alabama?
Yes. Alabama publishes 70 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 Alabama?
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.
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