Idaho · zones 5b–7b
When to plant kale in Idaho.
Sow or transplant between Apr 3 to May 1 in a typical year, keyed to Idaho's median last frost around May 11. A second, fall sowing fits Jun 28 to Aug 13. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Kale dates for a typical Idaho season.
1 · Start indoors
Feb 20 to Mar 20
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Apr 3 to May 1
Keyed to the ~May 11 last frost. Sow 0.25" deep, 16" apart.
Fall round
Jun 28 to Aug 13
Counted back from the ~Sep 28 first frost.
Harvest
~45 days later
~2 lb per plant over ~16 weeks.
Idaho spans more than one climate: Zone 6 is the most common zone, but the state runs 5b to 7b. 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.