Idaho · zones 5b–7b
When to plant sweet potatoes in Idaho.
Sow or transplant between Jun 17 to Aug 1 in a typical year, keyed to Idaho's median last frost around May 11. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Sweet Potatoes dates for a typical Idaho season.
1 · Start indoors
May 6 to Jun 20
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Jun 17 to Aug 1
Keyed to the ~May 11 last frost. Sow 3" deep, 14" apart.
Harvest
~110 days later
~2.5 lb per plant over ~1 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.