Washington · zones 6b–9a
When to plant zucchini in Washington.
Sow between Apr 21 to Aug 4 in a typical year, keyed to Washington's median last frost around Apr 14. A second, fall sowing fits Jul 4 to Jul 23. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Zucchini dates for a typical Washington season.
Direct sow
Apr 21 to Aug 4
Keyed to the ~Apr 14 last frost. Sow 1" deep, 24" apart.
Fall round
Jul 4 to Jul 23
Counted back from the ~Oct 18 first frost.
Harvest
~50 days later
~8 lb per plant over ~5 weeks.
Washington spans more than one climate: Zone 8 is the most common zone, but the state runs 6b to 9a. 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.