Montana · zones 4a–5b
When to plant carrots in Montana.
Sow between Apr 7 to May 10 in a typical year, keyed to Montana's median last frost around May 15. A second, fall sowing fits Jun 28 to Jul 24. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Carrots dates for a typical Montana season.
Direct sow
Apr 7 to May 10
Keyed to the ~May 15 last frost. Sow 0.25" deep, 2" apart.
Fall round
Jun 28 to Jul 24
Counted back from the ~Sep 23 first frost.
Harvest
~68 days later
~0.2 lb per plant over ~2 weeks.
Montana spans more than one climate: Zone 4 is the most common zone, but the state runs 4a to 5b. 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.