When to plant Lettuce in Colorado
In spring, from Mar 15 – May 15 in Grand Junction to May 20 – June 30 in Steamboat Springs.
In fall, from May 15 – July 15 in Steamboat Springs to July 15 – Sept 1 in Windsor.
USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.
| Place | Spring | Fall |
|---|---|---|
| Arvada | Apr 1 – June 1 | June 1 – Aug 1 |
| Aurora | Apr 15 – June 15 | July 15 – Sept 1 |
| Berthoud | Apr 15 – June 15 | June 1 – Aug 1 |
| Boulder | Apr 15 – June 15 | June 1 – Aug 1 |
| Brighton | Apr 1 – June 1 | July 15 – Sept 1 |
| Broomfield | Apr 1 – June 1 | July 15 – Sept 1 |
| Cañon City | Apr 1 – June 1 | July 15 – Sept 1 |
| Castle Pines | Apr 15 – June 15 | June 1 – Aug 1 |
| Castle Rock | Apr 15 – June 15 | June 1 – Aug 1 |
| Centennial | Apr 1 – June 1 | July 15 – Sept 1 |
| Colorado Springs | Apr 1 – June 1 | July 15 – Sept 1 |
| Commerce City | Apr 1 – June 1 | July 15 – Sept 1 |
| Denver | Apr 1 – June 1 | July 15 – Sept 1 |
| Durango | May 1 – June 30 | June 1 – Aug 1 |
| Englewood | Apr 1 – June 1 | July 15 – Sept 1 |
| Erie | Apr 15 – June 15 | June 1 – Aug 1 |
| Evans | Apr 1 – June 1 | July 15 – Sept 1 |
| Federal Heights | Apr 1 – June 1 | July 15 – Sept 1 |
| Firestone | Apr 15 – June 15 | June 1 – Aug 1 |
| Fort Collins | Apr 1 – June 1 | July 15 – Sept 1 |
| Fort Morgan | Apr 15 – June 15 | July 15 – Sept 1 |
| Fountain | Apr 1 – June 1 | July 15 – Sept 1 |
| Frederick | Apr 15 – June 15 | June 1 – Aug 1 |
| Fruita | Apr 1 – June 1 | July 15 – Sept 1 |
| Glenwood Springs | Apr 15 – June 15 | June 1 – Aug 1 |
| Golden | Apr 1 – June 1 | July 15 – Sept 1 |
| Grand Junction | Mar 15 – May 15 | July 15 – Sept 1 |
| Greeley | Apr 1 – June 1 | July 15 – Sept 1 |
| Greenwood Village | Apr 15 – June 15 | July 15 – Sept 1 |
| Johnstown | Apr 15 – June 15 | June 1 – Aug 1 |
| Lafayette | Apr 1 – June 1 | July 15 – Sept 1 |
| Lakewood | Apr 1 – June 1 | July 15 – Sept 1 |
| Littleton | Apr 1 – June 1 | July 15 – Sept 1 |
| Lone Tree | Apr 1 – June 1 | July 15 – Sept 1 |
| Longmont | Apr 15 – June 15 | June 1 – Aug 1 |
| Louisville | Apr 15 – June 15 | June 1 – Aug 1 |
| Loveland | Apr 15 – June 15 | June 1 – Aug 1 |
| Montrose | Apr 1 – June 1 | July 15 – Sept 1 |
| Monument | May 1 – June 30 | June 1 – Aug 1 |
| Northglenn | Apr 1 – June 1 | July 15 – Sept 1 |
| Parker | Apr 15 – June 15 | June 1 – Aug 1 |
| Pueblo | Apr 1 – June 1 | July 15 – Sept 1 |
| Rifle | Apr 15 – June 15 | June 1 – Aug 1 |
| Severance | Apr 1 – June 1 | July 15 – Sept 1 |
| Steamboat Springs | May 20 – June 30 | May 15 – July 15 |
| Sterling | Apr 1 – June 1 | July 15 – Sept 1 |
| Superior | Apr 15 – June 15 | June 1 – Aug 1 |
| Thornton | Apr 1 – June 1 | July 15 – Sept 1 |
| Timnath | Apr 1 – June 1 | July 15 – Sept 1 |
| Wellington | Apr 1 – June 1 | July 15 – Sept 1 |
| Westminster | Apr 1 – June 1 | July 15 – Sept 1 |
| Wheat Ridge | Apr 1 – June 1 | June 1 – Aug 1 |
| Windsor | Apr 1 – June 1 | July 15 – Sept 1 |
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), tables 4 and 5. Frost dates: NOAA U.S. Climate Normals 1991–2020. “—” means the place's frost date is outside the table. The full USDA table for leaf lettuce.