Cool-Season Vegetable

When to Plant Broccoli in Wisconsin

A nutrition powerhouse that thrives in cool weather. Harvest the main head, then enjoy weeks of side shoots.

The Short Answer

Broccoli are cold-tolerant and do well in Wisconsin's varied climate. You can direct sow 4 weeks before your last frost — that's as early as May 15 - Jun 1 in Northern Wisconsin. Wisconsin gardeners can also plant a fall crop. Rich agricultural soils in southern half. Sandy soils in central plain. Heavy clay in some lake...

Wisconsin Frost Dates

Your planting dates depend on which part of Wisconsin you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Northern Wisconsin 3b, 4a May 15 - Jun 1 Sep 10 - Sep 25
Central Wisconsin 4a, 4b May 5 - May 20 Sep 20 - Oct 5
Southern Wisconsin 4b, 5a, 5b Apr 25 - May 10 Oct 1 - Oct 15

Broccoli Planting Schedule for Wisconsin

Northern Wisconsin (Zones 3b, 4a)

Average last frost: May 15 - Jun 1 · Average first frost: Sep 10 - Sep 25

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks before frost
Direct Sow
4 wks before frost
Fall Planting
10 wks before first frost

Central Wisconsin (Zones 4a, 4b)

Average last frost: May 5 - May 20 · Average first frost: Sep 20 - Oct 5

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks before frost
Direct Sow
4 wks before frost
Fall Planting
10 wks before first frost

Southern Wisconsin (Zones 4b, 5a, 5b)

Average last frost: Apr 25 - May 10 · Average first frost: Oct 1 - Oct 15

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks before frost
Direct Sow
4 wks before frost
Fall Planting
10 wks before first frost

Growing Broccoli in Wisconsin

Broccoli in Wisconsin's Climate

Broccoli thrives in your cool climate. Spring planting works well — transplant 2-3 weeks before last frost. Unlike warmer regions where heat causes premature bolting, your moderate summer temperatures often allow extended broccoli harvests. Fall broccoli is equally productive. Northern Michigan, Minnesota, and Wisconsin can even grow broccoli through summer in cooler years.

Soil Considerations for Wisconsin

Rich agricultural soils in southern half. Sandy soils in central plain. Heavy clay in some lake regions. Generally fertile.

Wisconsin Climate & Growing Season

Cold winters. Warm summers. Lake Michigan moderates eastern climate. Good growing season in south. Short season in north. Broccoli can handle frost well, which is an advantage in Wisconsin's climate. You can push planting dates earlier in spring and extend into fall.

Growing season length varies across Wisconsin: Northern Wisconsin (3b, 4a) has a last frost around May 15 - Jun 1, while Southern Wisconsin (4b, 5a, 5b) sees frost end around Apr 25 - May 10. This difference matters for broccoli — but broccoli handle frost well, so the timing difference is less critical.

Growing Tips

Harvest main head while buds are tight. Side shoots will continue producing for weeks after the main harvest.

Companion Planting

Plant broccoli alongside these companions for better growth:

Beets Celery Onions Potatoes

Keep broccoli away from:

Tomatoes Peppers Strawberries

The Bottom Line

Broccoli can be grown successfully across Wisconsin, but your exact planting dates depend on which region you're in. Northern Wisconsin gardeners should plan around a May 15 - Jun 1 last frost, while those in Southern Wisconsin can typically plant earlier. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Broccoli Growing Guide National planting guide with all states Wisconsin Planting Calendar All plants for Wisconsin Broccoli in Alabama Alabama planting dates Broccoli in Alaska Alaska planting dates Broccoli in Arizona Arizona planting dates Broccoli in Arkansas Arkansas planting dates
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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