When to plant cauliflower in USDA Zone 5a

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.

Madison WI, Des Moines, southern MN, central MI. Average last spring frost May 8, first fall frost September 29 — a 144-day frost-free season.

Zone fit: excellent
Cauliflower is well suited to Zone 5a. Standard planting dates work with minor adjustments for microclimates.

Key dates

Start seeds indoors
March 20 – April 3
Transplant outdoors
April 10 – May 1
Expected first harvest
June 26 – July 24
Fall planting window
June 30 – July 21
Fall harvest window
September 15 – October 13

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 5a

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 5a

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.