When to plant onion in Oklahoma
Oklahoma spans USDA zones 6b–8a, so the right time to plant onion shifts by weeks across the state. The window to transplant seedlings outdoors runs from about February 15 in Ardmore to March 21 in Guymon — below are local dates for 45 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Transplant out |
|---|---|---|---|---|
| Oklahoma City | 7b | April 4 | November 2 | March 7 – March 21 |
| Tulsa | 7b | March 31 | November 4 | March 3 – March 17 |
| Norman | 7b | April 3 | November 3 | March 6 – March 20 |
| Broken Arrow | 7b | April 1 | November 1 | March 4 – March 18 |
| Edmond | 7b | April 10 | October 28 | March 13 – March 27 |
| Lawton | 7b | March 26 | November 7 | February 26 – March 12 |
| Moore | 7b | March 31 | November 5 | March 3 – March 17 |
| Midwest City | 7b | April 2 | November 5 | March 5 – March 19 |
Onion in Oklahoma: FAQ
When can I plant onion in Oklahoma?
Across Oklahoma, the time to transplant onion spans roughly February 15 in Ardmore to March 21 in Guymon, each following that city's local frost dates.
Does the onion planting date vary across Oklahoma?
Yes. Oklahoma publishes 45 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 Oklahoma?
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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