Soil Types in Wisconsin

Wisconsin has 718 zip codes in our database. The most common soil type is Loam, found in 0% of the state. Understanding your local soil type helps you choose the right plants and amendments for your garden.

Wisconsin spans USDA hardiness zones 4a through 6a. Your hardiness zone determines which perennial plants will survive winter in your area. Enter your zip code above to find your exact zone and get personalized planting recommendations.

Wisconsin has a unique geological feature: the Driftless Area in the southwestern part of the state was never glaciated, making it the only unglaciated region in the upper Midwest. This creates dramatic soil contrasts. The Driftless Area has thin, hilly soils developed from underlying limestone, sandstone, and shale — steep terrain with rock outcrops and stream valleys. The rest of Wisconsin was thoroughly glaciated, producing the deep, fertile soils that support the state's massive dairy industry. Northern Wisconsin has sandy glacial outwash and thin, acidic forest soils over Canadian Shield bedrock. The southeast, including the Milwaukee area, has deep, productive glacial till and lake deposits. Antigo silt loam, the state soil, is a productive northern Wisconsin soil formed in glacial till.

Wisconsin's growing season ranges from about 130 days in the northern lake country to 175 days in the southeastern corner. Milwaukee, moderated by Lake Michigan, averages about 175 frost-free days, with the last frost near April 25 and first frost in late October. Madison has about 160 days. Green Bay has 150 days. Northern communities like Hayward and Eagle River have just 110-130 frost-free days. Wisconsin's long winter dormancy actually benefits soil — the freeze-thaw cycles break up clay clods and the snow cover insulates and slowly provides moisture. Spring comes gradually, with gardeners learning patience as cold, wet soils slowly warm.

Wisconsin is 'America's Dairyland,' and the same glacial soils that grow excellent forage also produce outstanding vegetables. Potatoes are a major crop, especially in the central sandy plains around Stevens Point. Cranberries thrive in the acidic bogs of central Wisconsin — the state is the nation's top cranberry producer. Sweet corn, snap beans, and canning crops (peas, sweet corn, beets) make Wisconsin a processing vegetable powerhouse. For home gardens, cool-season crops are the safest bet statewide: peas, beans, lettuce, broccoli, carrots, and potatoes. Shorter-season tomato varieties succeed in southern and central areas. Apples, cherries (especially in Door County), and berries perform well in the glacial soils.

The UW-Madison Soil and Forage Lab provides soil testing for about $15-20. Wisconsin soils generally have good natural fertility from glacial deposits, with pH ranging from acidic in the north (5.0-5.5) to near-neutral in the south. Lime is commonly needed in northern and central Wisconsin. The sandy soils of the central plains need organic matter to hold water and nutrients — these same soils warm quickly in spring, giving sandy-soil gardeners an earlier start. Clay soils in the southeast stay cold and wet longer but reward patience with excellent fertility. Raised beds are popular across Wisconsin for earlier planting and better drainage. The state's strong community garden and Master Gardener traditions provide locally adapted growing advice.