When to plant radish in Colorado
Colorado spans USDA zones 5b–7a, so the right time to plant radish shifts by weeks across the state. The window to sow seed directly outdoors runs from about March 17 in Grand Junction to May 24 in Edwards — below are local dates for 70 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Direct sow |
|---|---|---|---|---|
| Denver | 6a | May 4 | October 8 | April 6 – May 18 |
| Colorado Springs | 6a | May 3 | October 8 | April 5 – May 17 |
| Aurora | 6a | May 7 | October 8 | April 9 – May 21 |
| Fort Collins | 5b | May 2 | October 7 | April 4 – May 16 |
| Lakewood | 6a | May 3 | October 7 | April 5 – May 17 |
| Thornton | 6a | May 2 | October 11 | April 4 – May 16 |
| Arvada | 6a | May 5 | October 5 | April 7 – May 19 |
| Westminster | 6a | May 2 | October 11 | April 4 – May 16 |
Radish in Colorado: FAQ
When can I plant radish in Colorado?
Across Colorado, the time to direct-sow radish spans roughly March 17 in Grand Junction to May 24 in Edwards, each following that city's local frost dates.
Does the radish planting date vary across Colorado?
Yes. Colorado publishes 70 cities with their own frost dates, so the right radish planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.
How long does radish take to grow in Colorado?
Radish takes about 22–30 days to reach harvest once planted — check that this fits inside your city's frost-free season on its place page.
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