Michigan · zones 4b–6b
When to plant zucchini in Michigan.
Sow between May 12 to Aug 25 in a typical year, keyed to Michigan's median last frost around May 5. A second, fall sowing fits Jun 24 to Jul 13. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Zucchini dates for a typical Michigan season.
Direct sow
May 12 to Aug 25
Keyed to the ~May 5 last frost. Sow 1" deep, 24" apart.
Fall round
Jun 24 to Jul 13
Counted back from the ~Oct 8 first frost.
Harvest
~50 days later
~8 lb per plant over ~5 weeks.
Michigan spans more than one climate: Zone 6 is the most common zone, but the state runs 4b to 6b. 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.