When to plant tomatoes in Minnesota
Minnesota’s average last spring frost is May 6, and the first fall frost typically arrives around September 28 — about 145 frost-free days (USDA zones 3a, 3b, 4a, 4b, 5a). Tomato needs 60–85 days to mature, which fits comfortably within Minnesota's growing season.
When to plant tomatoes in Minnesota: the short answer
For a spring planting, plant out May 6 – May 23, with seeds started indoors Mar 11 – Mar 25. Wait until the soil is at least 50°F and frost is over.
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow tomatoes in Minnesota, step by step
- Start seeds indoors (Mar 11 – Mar 25). Sow seeds ¼ inch deep in seed-starting mix under bright light. They take 5-10 days to sprout, fastest in soil around 80°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. They need at least six to eight hours of direct sun a day and loose soil at least 18 inches deep, with a pH between 5.5 and 7.5. Dig in compost before planting.
- Plant out (May 6 – May 23). Space plants about 24 inches apart in rows 36 inches apart. It is killed by frost, so nothing goes outside until the danger has passed.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: tomato hornworm, aphids, whitefly, flea beetle. Diseases and disorders: early blight, late blight, septoria leaf spot, fusarium wilt, blossom-end rot (calcium disorder).
- Harvest (from about Jul 12 – Aug 6). Tomato takes 60-85 days to reach harvest. Days to maturity counted from transplant. Bury 2/3 of the stem at transplanting for extra roots. Determinate types suit containers and one big harvest; indeterminate types need staking and produce until frost.
Figures come from our crop data; dates use Minnesota’s average frost dates. More in the full tomato growing guide.
Tomato planting dates by USDA zone in Minnesota
Minnesota spans USDA zones 3a, 3b, 4a, 4b, 5a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the tomato dates shift with them.
When to plant tomatoes in nearby states
Questions gardeners in Minnesota ask
When is the best time to plant tomatoes in Minnesota?
Plant tomato transplants outdoors in Minnesota between May 6 and May 23. That timing is set by Minnesota's average last spring frost of May 6.
When should I start tomato seeds indoors in Minnesota?
Start seeds indoors between March 11 and March 25, about 7 weeks before the last frost, so the seedlings are ready to plant out from May 6.
What is the latest I can plant tomatoes in Minnesota?
About July 30. Tomatoes need at least 60 days to mature after transplanting, and frost around September 28 ends the season, so later plantings risk being cut short.
When will tomatoes planted in Minnesota be ready to harvest?
Planted on time, tomatoes are usually ready from about July 12 to August 6, 60-85 days after transplanting.
When is the last frost in Minnesota?
On average around May 6, with the first fall frost around September 28 - about 145 frost-free days. Your town may differ by two weeks or more.