Minnesota · zones 3b–5a
When to plant tomatoes in Minnesota.
Sow or transplant between May 12 to Jul 6 in a typical year, keyed to Minnesota's median last frost around May 5. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Tomatoes dates for a typical Minnesota season.
1 · Start indoors
Mar 31 to May 25
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
May 12 to Jul 6
Keyed to the ~May 5 last frost. Sow 0.25" deep, 24" apart.
Harvest
~73 days later
~12 lb per plant over ~8 weeks.
Minnesota spans more than one climate: Zone 4 is the most common zone, but the state runs 3b to 5a. 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.
In Minnesota: watch for
The pests that find tomatoes here.
The short season here, about 149 frost-free days, keeps tomato, slicing in front of tomato hornworm only briefly. One early row cover usually carries a planting through the worst of it.
Big green caterpillars strip leaves and leave black droppings.
Organic fix: Handpick at dusk; spray Bt on the young ones.
Clusters on new growth, sticky leaves, curling tips.
Organic fix: Blast with water, then insecticidal soap or neem.
Dark spots with concentric rings, starting on the lowest, oldest leaves.
Organic fix: Remove affected leaves, mulch to stop soil splash, space for airflow.
Greasy, water-soaked blotches in cool, wet spells. No rings, and not bottom-up.
Organic fix: Pull infected plants fast, keep leaves dry, use neem as a preventive.
Septoria leaf spot
Many small tan spots with dark brown edges, low leaves first, no rings inside.
Organic fix: Strip the lowest leaves, mulch against soil splash, stake for airflow.
Your season math: Minnesota gives tomatoes about 149 frost-free days, and it needs roughly 73 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting tomatoes in Minnesota: questions
When should I plant tomatoes in Minnesota?+
In a typical Minnesota year, sow tomatoes or set out transplants between May 12 to Jul 6, keyed to the state's median last frost around May 5. Your exact dates shift with your ZIP code and microclimate.
When do I start tomatoes seeds indoors in Minnesota?+
Start seeds inside about 6 weeks before set-out: roughly Mar 31 to May 25 for a typical Minnesota season.
What USDA zone is Minnesota?+
Minnesota spans zones 3b–5a, mostly zone 4. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many tomatoes plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.