Colorado · zones 5a–7a
When to plant kale in Colorado.
Sow or transplant between Apr 1 to Apr 29 in a typical year, keyed to Colorado's median last frost around May 9. A second, fall sowing fits Jun 29 to Aug 14. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Kale dates for a typical Colorado season.
1 · Start indoors
Feb 18 to Mar 18
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Apr 1 to Apr 29
Keyed to the ~May 9 last frost. Sow 0.25" deep, 16" apart.
Fall round
Jun 29 to Aug 14
Counted back from the ~Sep 29 first frost.
Harvest
~45 days later
~2 lb per plant over ~16 weeks.
Colorado spans more than one climate: Zone 6 is the most common zone, but the state runs 5a to 7a. That's why the planner works from your ZIP code's frost dates, not your zone — mountain and coastal gardens in the same state can be three weeks apart.