Growing zucchini in zone 3
Direct-sow after frost and stand back. Harvest at 6–8 inches — they double in size overnight in July. A second sowing in midsummer keeps production going after vine borers or mildew take the first planting.
Zone 3 covers northern Minnesota and North Dakota, northern Maine, high mountain valleys — roughly 120 frost-free days — start warm-season crops indoors, lean on cool-season crops. Zone dates are medians: frost timing varies within a zone with elevation and terrain, so treat these windows as a solid default and refine them with your own city’s dates below.
Make it local
These windows use zone 3's typical frost dates (last frost ~May 15, first frost ~Sep 20). For windows computed from your frost dates, run the ZIP code frost lookup and open the planting calendar — it remembers your city. The seed starting scheduler turns the whole seed rack into one printable, date-sorted list.
Frequently asked questions
When do I plant zucchini in zone 3?
Transplant May 22 – May 29, counted from zone 3's typical last frost around May 15. It has no frost tolerance — a late frost after planting means covering it or replanting.
When should I start seeds indoors for zucchini in zone 3?
Sow indoors Apr 17 – Apr 24 — that's 4 to 3 weeks before the typical May 15 last frost, giving sturdy transplants exactly when the garden is ready for them.
Can I direct sow zucchini in zone 3?
Yes — direct sow May 22 – May 29. Transplants buy a head start, but direct-sown plants catch up quickly once soil warms.