Hawaii · zones 12a–12a
When to plant zucchini in Hawaii.
Sow between Jan 8 to Apr 23 in a typical year, keyed to Hawaii's median last frost around Jan 1. A second, fall sowing fits Sep 16 to Oct 5. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Zucchini dates for a typical Hawaii season.
Direct sow
Jan 8 to Apr 23
Keyed to the ~Jan 1 last frost. Sow 1" deep, 24" apart.
Fall round
Sep 16 to Oct 5
Counted back from the ~Dec 31 first frost.
Harvest
~50 days later
~8 lb per plant over ~5 weeks.
Hawaii spans more than one climate: Zone 12 is the most common zone, but the state runs 12a to 12a. 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.