When to plant Onions in Wyoming
In spring, from Apr 10 – May 1 in Casper to May 10 – June 10 in Laramie.
In fall, May 1 – June 10.
Dates are for setting out plants. USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.
| Place | Spring | Fall |
|---|---|---|
| Casper | Apr 10 – May 1 | Spring-planted |
| Cheyenne | Apr 10 – May 1 | Spring-planted |
| Cody | Apr 10 – May 1 | Spring-planted |
| Evanston | May 10 – June 10 | May 1 – June 10 |
| Gillette | Apr 10 – May 1 | Spring-planted |
| Green River | Apr 20 – May 15 | Spring-planted |
| Jackson | May 10 – June 10 | May 1 – June 10 |
| Laramie | May 10 – June 10 | May 1 – June 10 |
| Riverton | Apr 10 – May 1 | Spring-planted |
| Rock Springs | Apr 20 – May 15 | Spring-planted |
| Sheridan | Apr 20 – May 15 | Spring-planted |
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), tables 4 and 5. Frost dates: NOAA U.S. Climate Normals 1991–2020. The full USDA table for onion plants.