When to plant mustard greens in Colorado
Colorado spans USDA zones 5b–7a, so the right time to plant mustard greens 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 |
Mustard Greens in Colorado: FAQ
When can I plant mustard greens in Colorado?
Across Colorado, the time to direct-sow mustard greens spans roughly March 17 in Grand Junction to May 24 in Edwards, each following that city's local frost dates.
Does the mustard greens planting date vary across Colorado?
Yes. Colorado publishes 70 cities with their own frost dates, so the right mustard greens 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 mustard greens take to grow in Colorado?
Mustard Greens takes about 30–45 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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