When to Plant Onions in Utah
In Utah, the time to plant onions outside runs from Feb 14 – Feb 28 in St. George to May 5 – May 19 in Eagle Mountain. In Salt Lake City, it's Mar 3 – Mar 17. The average last spring frost differs by about 11 weeks across the state (Mar 14 in St. George, Jun 2 in Eagle Mountain), so use the dates for the town nearest you.
Onions are cold-hardy. Plant sets or transplants early so they grow leaves before long summer days trigger bulbing.
- Start indoors: 10–12 weeks before the last frost.
- Plant outside: 2–4 weeks before the last frost.
Onions planting dates in Utah by city
| City | Zone | Start indoors | Plant outside |
|---|---|---|---|
| American Fork | 7a | Jan 23 – Feb 6 | Mar 20 – Apr 3 |
| Bountiful | 6b | Jan 31 – Feb 14 | Mar 28 – Apr 11 |
| Cedar City | 6b | Feb 9 – Feb 23 | Apr 6 – Apr 20 |
| Clearfield | 7a | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Cottonwood Heights | 7b | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Draper | 7a | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Eagle Mountain | 6b | Mar 10 – Mar 24 | May 5 – May 19 |
| Farmington | 7b | Jan 25 – Feb 8 | Mar 22 – Apr 5 |
| Herriman | 7a | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Holladay | 7b | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Hurricane | 8b | Jan 7 – Jan 21 | Mar 4 – Mar 18 |
| Kaysville | 7b | Jan 25 – Feb 8 | Mar 22 – Apr 5 |
| Kearns metro township | 7b | Jan 14 – Jan 28 | Mar 11 – Mar 25 |
| Layton | 7a | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Lehi | 7a | Feb 5 – Feb 19 | Apr 2 – Apr 16 |
| Logan | 6a | Feb 13 – Feb 27 | Apr 10 – Apr 24 |
| Magna metro township | 7b | Jan 9 – Jan 23 | Mar 6 – Mar 20 |
| Midvale | 7b | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Millcreek | 7b | Jan 31 – Feb 14 | Mar 28 – Apr 11 |
| Murray | 7b | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Ogden | 6b | Jan 27 – Feb 10 | Mar 24 – Apr 7 |
| Orem | 7a | Jan 25 – Feb 8 | Mar 22 – Apr 5 |
| Pleasant Grove | 7a | Jan 23 – Feb 6 | Mar 20 – Apr 3 |
| Provo | 7a | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Riverton | 7a | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Roy | 7a | Jan 28 – Feb 11 | Mar 25 – Apr 8 |
| Salt Lake City | 7b | Jan 6 – Jan 20 | Mar 3 – Mar 17 |
| Sandy | 7b | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Saratoga Springs | 7a | Feb 5 – Feb 19 | Apr 2 – Apr 16 |
| South Jordan | 7a | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| South Salt Lake | 7b | Jan 6 – Jan 20 | Mar 3 – Mar 17 |
| Spanish Fork | 7a | Jan 31 – Feb 14 | Mar 28 – Apr 11 |
| Springville | 7a | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| St. George | 8b | Dec 20 – Jan 3 | Feb 14 – Feb 28 |
| Syracuse | 7b | Jan 28 – Feb 11 | Mar 25 – Apr 8 |
| Taylorsville | 7b | Jan 6 – Jan 20 | Mar 3 – Mar 17 |
| Tooele | 7a | Feb 7 – Feb 21 | Apr 4 – Apr 18 |
| Washington | 8b | Dec 20 – Jan 3 | Feb 14 – Feb 28 |
| West Jordan | 7b | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| West Valley City | 7b | Jan 14 – Jan 28 | Mar 11 – Mar 25 |
Calculated from each town's average (50%) frost dates, from the nearest NOAA station (1991–2020). Typical dates for the 2027 planting season, based on NOAA's 1991–2020 averages. They are long-term odds, not a forecast: always check your local forecast before planting. Zones: 2023 USDA Plant Hardiness Zone Map (USDA-ARS and Oregon State University). Not the official map; see planthardiness.ars.usda.gov.
See all frost dates in Utah, or the general guide to when to plant onions.
Getting beds ready? Work out how much raised bed soil, compost or mulch you need with our sister site, Yard Coverage.