St. Croix County Soil Data
St. Croix County, Wisconsin
USDA SSURGO / PHZMAvg pH
5.9
Texture
Loam
Drainage
N/A
Organic Matter
3.9%
Hydrologic Group
N/A
Data Story
About Soil in St. Croix County, Wisconsin
Western Wisconsin's Mildly Acidic Soil
St. Croix County features a soil pH of 5.90, which is higher than the Wisconsin average of 5.63. While still acidic compared to the national median of 6.5, it provides a favorable environment for many traditional field crops. Local data does not specify the dominant taxonomic order, but the pH suggests high chemical availability.
Silt-Heavy Loams Drive Workability
Silt makes up 44.0% of the soil, paired with 40.2% sand and 13.5% clay. This silt-dominant mixture creates a smooth, workable texture that is less abrasive than sandy soils. The moderate clay content ensures that nutrients don't wash away during heavy spring rains.
Efficient Water Use with Leaner Organic Matter
Organic matter content is 3.91%, which is lower than the state's 11.02% average but nearly double the national average. Despite the lower organic levels, the available water capacity of 0.189 in/in remains close to the state average of 0.204 in/in. This indicates a soil that uses its resources efficiently to support plant growth.
Moderate Drainage for Field and Forest
Official drainage classes and hydrologic groups are not listed in the current dataset. However, the high silt and sand combination typically allows for steady drainage without the risk of extreme drought. This stability is a key reason why the county is a agricultural powerhouse in the region.
Resilient Zone 4b Cultivation
St. Croix falls into USDA Hardiness Zone 4b, requiring plants that can handle deep winter frosts. The silt-rich soil is ideal for corn, soybeans, and hardy garden vegetables like kale and peas. The manageable acidity and balanced texture make it an inviting environment for both commercial farmers and home gardeners.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Hydrologic group data not available.
Drainage Class
Drainage class data not available.
Soil Profile
Dominant texture: Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 5.9. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does St. Croix County have?
St. Croix County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 40% sand, 44% silt, and 14% clay. Loamy soils hold moisture well and support a wide range of plants.
Is St. Croix County's soil acidic or alkaline?
St. Croix County's soil has a pH of 5.9, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for St. Croix County?
Drainage class data is not currently available for St. Croix County.
What crops or plants grow well in St. Croix County's soil?
Based on St. Croix County's Loam texture, pH of 5.9, and drainage class, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens.
What USDA soil order is found in St. Croix County?
The dominant USDA soil order for St. Croix County is not currently available in our dataset.
Soil & Planting Advisory: St. Croix County
Soil Verdict
St. Croix County is in USDA hardiness zone 4b, a cold climate zone. where winter lows can reach -25°F. Soils here experience deep freeze cycles that can disrupt structure, kill shallow roots, and slow microbial activity for months each year.
Planting Guidance
Focus on cold-hardy perennials, native grasses, and conifers. The short growing window favors plants with low heat requirements. With extreme winter lows, any marginally hardy plants need heavy mulch and wind protection. Always match plant selections to the specific microclimate of your property — low spots, slopes, and wind exposure can shift effective hardiness by half a zone.
Soil Implications
Deep winter freezing can create soil heaving that pushes shallow-rooted plants out of the ground; add 3-4 inches of organic mulch each fall. Soil drainage is critical — frozen, waterlogged soil kills roots faster than cold alone. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
St. Croix County is somewhat cooler than the Wisconsin statewide average.
Planning your lawn? View lawn care data for St. Croix County on LawnByCounty.com →
Other Counties in Wisconsin
Soil data sourced from USDA SSURGO via Soil Data Access. Data is informational only and should not be used as a substitute for on-site soil testing. Contact your local NRCS office for site-specific soil information.