Colorado · zones 5a–7a
When to plant garlic in Colorado.
Colorado's window for garlic runs on the fall side of the season. A second, fall sowing fits Aug 29 to Oct 14. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Garlic dates for a typical Colorado season.
Fall round
Aug 29 to Oct 14
Counted back from the ~Sep 29 first frost.
Harvest
~240 days later
~0.2 lb per plant over ~1 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.