Arizona · zones 5b–10a
When to plant watermelon in Arizona.
Sow between Feb 26 to Apr 14 in a typical year, keyed to Arizona's median last frost around Feb 5. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Watermelon dates for a typical Arizona season.
Direct sow
Feb 26 to Apr 14
Keyed to the ~Feb 5 last frost. Sow 1" deep, 36" apart.
Harvest
~85 days later
~20 lb per plant over ~3 weeks.
Arizona spans more than one climate: Zone 9 is the most common zone, but the state runs 5b to 10a. 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.