When to plant cauliflower 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). Cauliflower needs 60–90 days to mature, which fits comfortably within Minnesota's growing season.
When to plant cauliflower 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 cauliflower 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 7.5. 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. It needs plenty of water; keep the soil evenly moist and never let it dry out.
- Watch for pests and problems. Pests: cabbage worm, cabbage looper, aphids, cabbage root maggot. Diseases and disorders: clubroot, black rot, downy mildew.
- Harvest (from about Jun 21 – Jul 21). Cauliflower takes 60-90 days to reach harvest. The fussiest brassica - any check from cold, heat, or drought ruins the head. Fall crops are far more reliable than spring. Blanch white types by tying leaves over the curd.
Figures come from our crop data; dates use Minnesota’s average frost dates. More in the full cauliflower growing guide.
Cauliflower 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 cauliflower dates shift with them.
When to plant cauliflower in nearby states
Questions gardeners in Minnesota ask
When is the best time to plant cauliflower in Minnesota?
Plant cauliflower 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 cauliflower 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 cauliflower 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 cauliflower planted in Minnesota be ready to harvest?
Planted on time, cauliflower is usually ready from about June 21 to July 21, 60-90 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.