When to plant broccoli 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). Broccoli needs 60–85 days to mature, which fits comfortably within Minnesota's growing season.
When to plant broccoli in Minnesota: the short answer
For a spring planting, plant out Apr 15 – May 2, with seeds started indoors Mar 18 – Apr 1. Seeds germinate in soil from 45 to 85°F.
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 broccoli in Minnesota, step by step
- Start seeds indoors (Mar 18 – Apr 1). Sow seeds ½ inch deep in seed-starting mix under bright light. They take 5-10 days to sprout, fastest in soil around 75°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 18 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Plant out (Apr 15 – May 2). Space plants about 18 inches apart in rows 30 inches apart. It tolerates a light frost but not a hard freeze. As a cool-season crop it does best before summer heat arrives in Minnesota.
- 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: cabbage worm, cabbage looper, aphids, flea beetle, cabbage root maggot. Diseases and disorders: clubroot, black rot, downy mildew.
- Harvest (from about Jun 21 – Jul 16). Broccoli takes 60-85 days to reach harvest. Days to maturity counted from transplant. Keep cutting side shoots after the main head for weeks. Spring crop must size up before heat or it buttons.
Figures come from our crop data; dates use Minnesota’s average frost dates. More in the full broccoli growing guide.
Broccoli 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 broccoli dates shift with them.
When to plant broccoli in nearby states
Questions gardeners in Minnesota ask
When is the best time to plant broccoli in Minnesota?
Plant broccoli transplants outdoors in Minnesota between April 15 and May 2. That timing is set by Minnesota's average last spring frost of May 6.
When should I start broccoli seeds indoors in Minnesota?
Start seeds indoors between March 18 and April 1, about 6 weeks before the last frost, so the seedlings are ready to plant out from April 15.
Can I plant broccoli in the fall in Minnesota?
Yes. For a fall crop, start transplants between June 19 and July 6, so the crop matures in cool weather before Minnesota's first frost around September 28.
When will broccoli planted in Minnesota be ready to harvest?
Planted on time, broccoli is usually ready from about June 21 to July 16, 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.