Idaho · zones 5b–7b
When to plant broccoli in Idaho.
Sow or transplant between Mar 20 to Apr 17 in a typical year, keyed to Idaho's median last frost around May 11. A second, fall sowing fits Jun 14 to Jul 24. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Broccoli dates for a typical Idaho season.
1 · Start indoors
Feb 6 to Mar 6
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Mar 20 to Apr 17
Keyed to the ~May 11 last frost. Sow 0.5" deep, 18" apart.
Fall round
Jun 14 to Jul 24
Counted back from the ~Sep 28 first frost.
Harvest
~60 days later
~1.2 lb per plant over ~3 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.