When to plant sweet corn 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). Sweet Corn needs 60–100 days to mature, which fits comfortably within Minnesota's growing season.
When to plant sweet corn in Minnesota: the short answer
For a spring planting, sow May 8 – May 27. Wait until the soil is at least 55°F and frost is over.
Succession sow again in Minnesota: May 27 · Jun 10 · Jun 24 · Jul 8
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 sweet corn in Minnesota, step by step
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 24 inches deep, with a pH between 5.8 and 7.0. Dig in compost before planting.
- Sow outdoors (May 8 – May 27). Space plants about 10 inches apart in rows 30 inches apart, sowing seed 1.5 inches deep. It is killed by frost, so nothing goes outside until the danger has passed.
- Water and feed. It needs plenty of water; keep the soil evenly moist and never let it dry out.
- Watch for pests and problems. Pests: corn earworm, European corn borer, corn rootworm, raccoons. Diseases and disorders: common smut, common rust, Stewart's wilt.
- Harvest (from about Jul 12 – Aug 21). Sweet Corn takes 60-100 days to reach harvest. Plant in a block of at least 4 short rows, not one long row, or the ears fill unevenly. Keep sugar-enhanced and supersweet types isolated from field corn. Succeed by sowing every 2 weeks or planting early/mid/late varieties together.
Figures come from our crop data; dates use Minnesota’s average frost dates. More in the full sweet corn growing guide.
Sweet Corn 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 sweet corn dates shift with them.
When to plant sweet corn in nearby states
Questions gardeners in Minnesota ask
When is the best time to plant sweet corn in Minnesota?
Sow sweet corn in Minnesota between May 8 and May 27. That timing is set by Minnesota's average last spring frost of May 6.
What is the latest I can plant sweet corn in Minnesota?
About July 30. Sweet corn needs at least 60 days to mature, and frost around September 28 ends the season, so later plantings risk being cut short.
When will sweet corn planted in Minnesota be ready to harvest?
Planted on time, sweet corn is usually ready from about July 12 to August 21, 60-100 days after sowing.
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.