Cool-Season Vegetable

When to Plant Spinach in Wisconsin

Fast from seed to salad. Spinach bolts in heat, so plant early in spring and again in fall.

The Short Answer

Spinach are cold-tolerant and do well in Wisconsin's varied climate. You can direct sow 6 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

Spinach Planting Schedule for Wisconsin

Northern Wisconsin (Zones 3b, 4a)

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

Direct Sow
6 wks before frost
Fall Planting
6 wks before first frost

Central Wisconsin (Zones 4a, 4b)

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

Direct Sow
6 wks before frost
Fall Planting
6 wks before first frost

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

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

Direct Sow
6 wks before frost
Fall Planting
6 wks before first frost

Growing Spinach in Wisconsin

Spinach in Wisconsin's Climate

Your cool climate extends the spinach season significantly compared to warmer zones. Direct sow as soon as soil thaws — spinach germinates in soil as cool as 35°F. Michigan and Minnesota gardeners may get 6-8 weeks of production before bolting versus 3-4 weeks in the South. Fall spinach from an August sowing is equally productive and often superior in quality.

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. Spinach 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 spinach — adjust your planting dates to match your specific region.

Growing Tips

Direct sow as soon as soil can be worked in spring. For fall, plant 6-8 weeks before first frost.

Companion Planting

Plant spinach alongside these companions for better growth:

Strawberries Peas Radishes

The Bottom Line

Spinach 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

Spinach Growing Guide National planting guide with all states Wisconsin Planting Calendar All plants for Wisconsin Spinach in Alabama Alabama planting dates Spinach in Alaska Alaska planting dates Spinach in Arizona Arizona planting dates Spinach 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

Ready to Start Planting?

Enter your zip code and pick your plant. We'll tell you exactly when to plant, start seeds, and harvest — based on where you live.

Find Your Planting Dates