Oklahoma · zones 6b–7b
When to plant spinach in Oklahoma.
Sow between Feb 6 to Mar 20 in a typical year, keyed to Oklahoma's median last frost around Mar 30. A second, fall sowing fits Aug 21 to Oct 9. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Spinach dates for a typical Oklahoma season.
Direct sow
Feb 6 to Mar 20
Keyed to the ~Mar 30 last frost. Sow 0.5" deep, 3" apart.
Fall round
Aug 21 to Oct 9
Counted back from the ~Nov 4 first frost.
Harvest
~42 days later
~0.25 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.