Iowa · zones 4b–6a
When to plant cucumbers in Iowa.
Sow between May 8 to Aug 7 in a typical year, keyed to Iowa's median last frost around May 1. A second, fall sowing fits Jun 6 to Jul 7. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Cucumbers dates for a typical Iowa season.
Direct sow
May 8 to Aug 7
Keyed to the ~May 1 last frost. Sow 1" deep, 12" apart.
Fall round
Jun 6 to Jul 7
Counted back from the ~Oct 7 first frost.
Harvest
~60 days later
~5 lb per plant over ~5 weeks.
Iowa spans more than one climate: Zone 5 is the most common zone, but the state runs 4b to 6a. 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.