When to plant Radishes in Colorado
In spring, from Mar 1 – May 1 in Grand Junction to May 15 – June 1 in Steamboat Springs.
In fall, from May 1 – Aug 1 in Steamboat Springs to Aug 1 – Oct 1 in Grand Junction.
USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.
| Place | Spring | Fall |
|---|---|---|
| Arvada | Mar 20 – May 10 | July 1 – Sept 1 |
| Aurora | Apr 1 – June 1 | July 15 – Sept 15 |
| Berthoud | Apr 1 – June 1 | July 1 – Sept 1 |
| Boulder | Apr 1 – June 1 | July 1 – Sept 1 |
| Brighton | Mar 20 – May 10 | July 15 – Sept 15 |
| Broomfield | Mar 20 – May 10 | July 15 – Sept 15 |
| Cañon City | Mar 20 – May 10 | July 15 – Sept 15 |
| Castle Pines | Apr 1 – June 1 | July 1 – Sept 1 |
| Castle Rock | Apr 1 – June 1 | July 1 – Sept 1 |
| Centennial | Mar 20 – May 10 | July 15 – Sept 15 |
| Colorado Springs | Mar 20 – May 10 | July 15 – Sept 15 |
| Commerce City | Mar 20 – May 10 | July 15 – Sept 15 |
| Denver | Mar 20 – May 10 | July 15 – Sept 15 |
| Durango | Apr 15 – June 15 | July 1 – Sept 1 |
| Englewood | Mar 20 – May 10 | July 15 – Sept 15 |
| Erie | Apr 1 – June 1 | July 1 – Sept 1 |
| Evans | Mar 20 – May 10 | July 15 – Sept 15 |
| Federal Heights | Mar 20 – May 10 | July 15 – Sept 15 |
| Firestone | Apr 1 – June 1 | July 1 – Sept 1 |
| Fort Collins | Mar 20 – May 10 | July 15 – Sept 15 |
| Fort Morgan | Apr 1 – June 1 | July 15 – Sept 15 |
| Fountain | Mar 20 – May 10 | July 15 – Sept 15 |
| Frederick | Apr 1 – June 1 | July 1 – Sept 1 |
| Fruita | Mar 20 – May 10 | July 15 – Sept 15 |
| Glenwood Springs | Apr 1 – June 1 | July 1 – Sept 1 |
| Golden | Mar 20 – May 10 | July 15 – Sept 15 |
| Grand Junction | Mar 1 – May 1 | Aug 1 – Oct 1 |
| Greeley | Mar 20 – May 10 | July 15 – Sept 15 |
| Greenwood Village | Apr 1 – June 1 | July 15 – Sept 15 |
| Johnstown | Apr 1 – June 1 | July 1 – Sept 1 |
| Lafayette | Mar 20 – May 10 | July 15 – Sept 15 |
| Lakewood | Mar 20 – May 10 | July 15 – Sept 15 |
| Littleton | Mar 20 – May 10 | July 15 – Sept 15 |
| Lone Tree | Mar 20 – May 10 | July 15 – Sept 15 |
| Longmont | Apr 1 – June 1 | July 1 – Sept 1 |
| Louisville | Apr 1 – June 1 | July 1 – Sept 1 |
| Loveland | Apr 1 – June 1 | July 1 – Sept 1 |
| Montrose | Mar 20 – May 10 | July 15 – Sept 15 |
| Monument | Apr 15 – June 15 | July 1 – Sept 1 |
| Northglenn | Mar 20 – May 10 | July 15 – Sept 15 |
| Parker | Apr 1 – June 1 | July 1 – Sept 1 |
| Pueblo | Mar 20 – May 10 | July 15 – Sept 15 |
| Rifle | Apr 1 – June 1 | July 1 – Sept 1 |
| Severance | Mar 20 – May 10 | July 15 – Sept 15 |
| Steamboat Springs | May 15 – June 1 | May 1 – Aug 1 |
| Sterling | Mar 20 – May 10 | July 15 – Sept 15 |
| Superior | Apr 1 – June 1 | July 1 – Sept 1 |
| Thornton | Mar 20 – May 10 | July 15 – Sept 15 |
| Timnath | Mar 20 – May 10 | July 15 – Sept 15 |
| Wellington | Mar 20 – May 10 | July 15 – Sept 15 |
| Westminster | Mar 20 – May 10 | July 15 – Sept 15 |
| Wheat Ridge | Mar 20 – May 10 | July 1 – Sept 1 |
| Windsor | Mar 20 – May 10 | July 15 – Sept 15 |
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 radishes.