Oklahoma · zones 6b–7b
When to plant sweet potatoes in Oklahoma.
Sow or transplant between May 6 to Jun 20 in a typical year, keyed to Oklahoma's median last frost around Mar 30. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Sweet Potatoes dates for a typical Oklahoma season.
1 · Start indoors
Mar 25 to May 9
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
May 6 to Jun 20
Keyed to the ~Mar 30 last frost. Sow 3" deep, 14" apart.
Harvest
~110 days later
~2.5 lb per plant over ~1 weeks.
Oklahoma spans more than one climate: Zone 7 is the most common zone, but the state runs 6b 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.