When to Plant Sweet Corn in Wyoming
In Wyoming, the time to sow sweet corn outside runs from May 17 – May 31 in Casper to Jun 27 – Jul 11 in Jackson. In Cheyenne, it's May 21 – Jun 4. The average last spring frost differs by about 6 weeks across the state (May 10 in Casper, Jun 20 in Jackson), so use the dates for the town nearest you.
Sow corn in blocks rather than single rows so it pollinates well. Wait for soil around 60°F.
- Sow outside: 1–3 weeks after the last frost.
Sweet Corn planting dates in Wyoming by city
| City | Zone | Sow outside |
|---|---|---|
| Casper | 5a | May 17 – May 31 |
| Cheyenne | 5b | May 21 – Jun 4 |
| Cody | 5a | May 19 – Jun 2 |
| Douglas | 5a | May 26 – Jun 9 |
| Evanston | 5a | Jun 19 – Jul 3 |
| Gillette | 4b | May 22 – Jun 5 |
| Green River | 5a | May 31 – Jun 14 |
| Jackson | 4b | Jun 27 – Jul 11 |
| Lander | 5a | May 25 – Jun 8 |
| Laramie | 4a | Jun 14 – Jun 28 |
| Powell | 5a | May 26 – Jun 9 |
| Rawlins | 5a | May 24 – Jun 7 |
| Riverton | 5a | May 19 – Jun 2 |
| Rock Springs | 5a | May 31 – Jun 14 |
| Sheridan | 5a | May 28 – Jun 11 |
| Torrington | 5a | May 18 – Jun 1 |
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 Wyoming, or the general guide to when to plant sweet corn.
Getting beds ready? Work out how much raised bed soil, compost or mulch you need with our sister site, Yard Coverage.