When to plant cauliflower in USDA Zone 4a

Plan your cauliflower planting around local frost risk and soil temperature, then work backward from the harvest week your buyers need. The calendar below is a starting point, not a field-level weather forecast.

Fargo ND, northern MN, northern WI, northern ME. Average last spring frost May 22, first fall frost September 15 — a 116-day frost-free season.

Zone fit: excellent
Cauliflower is well suited to Zone 4a. Standard planting dates work with minor adjustments for microclimates.

Key dates

Start seeds indoors
April 3 – April 17
Transplant outdoors
April 24 – May 15
Expected first harvest
July 10 – August 7
Fall planting window
June 16 – July 7
Fall harvest window
September 1 – September 29

Windows are calculated from your zone's average frost dates. Adjust ±1 week for microclimates, elevation, and your own frost records.

Spacing and soil

Plant spacing
18″
Row spacing
30″
Seed depth
0.25″
Soil temperature
55–75°F
Frost tolerance
half-hardy
Days to harvest
70 days

Grower notes for Zone 4a

Blanch heads by folding outer leaves over developing curds when they reach 2 inches, unless growing a self-blanching variety.

Plant near: celery, onions

Keep away from: tomatoes, strawberries

Other brassicas for Zone 4a

Same crop, other zones

Track your own plantings

BAU Farm Intelligence turns these windows into per-field tasks — indoor seed-start reminders, transplant dates, harvest projections — using your farm's actual frost history.