Iron County Soil Data
Iron County, Wisconsin
USDA SSURGO / PHZMAvg pH
4.4
Texture
Loam
Drainage
Well drained
Organic Matter
33.1%
Hydrologic Group
N/A
Data Story
About Soil in Iron County, Wisconsin
Acidic Entisols of the North
Iron County is defined by highly acidic Entisols with an average pH of 4.38, significantly lower than the national median of 6.5. This pH level is also well below the Wisconsin state average of 5.63, requiring specific plant selections or soil amendments. These young soils reflect the rugged, untamed nature of the northern landscape.
Sandy Texture with Minimal Clay
The soil contains 35.5% sand and 27.8% silt, with a very low clay content of only 5.5%. This coarse makeup results in a loose structure that is easy to dig but may struggle to hold onto certain nutrients. The lack of clay means the soil is highly resistant to becoming sticky or waterlogged.
Exceptional Organic Matter Levels
The county boasts a staggering 33.12% organic matter content, triple the state average of 11.02%. This rich organic layer drives an available water capacity of 0.296 in/in, which is significantly higher than the state's 0.204 average. These numbers point to a soil that is incredibly sponge-like and nutrient-dense despite its acidity.
Well Drained for High Runoff
Classified as well-drained, this soil allows water to move through the profile quickly, reducing the risk of root rot. This rapid drainage is essential for managing the heavy snowmelt common in the region. Builders and gardeners alike benefit from the predictable way water exits the upper soil layers.
Gardening in Cold-Hardy Zone 4a
Zone 4a's short growing season favors acid-loving plants like blueberries and cranberries that thrive in low pH. While the climate is challenging, the 66.0 soil score supports a robust natural ecosystem. Focus on native, cold-hardy species to make the most of this unique northern soil.
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
Well drained
Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.
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 4.4. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Iron County have?
Iron County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 36% sand, 28% silt, and 5% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Iron County's soil acidic or alkaline?
Iron County's soil has a low pH of 4.4, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Iron County?
Iron County has a dominant drainage class of "Well drained." Well-drained soils allow excess water to move through quickly, reducing waterlogging risk and supporting most field and garden crops.
What crops or plants grow well in Iron County's soil?
Based on Iron County's Loam texture, pH of 4.4, and Well drained, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens, most annual and perennial crops.
What USDA soil order is found in Iron County?
Iron County's dominant soil order is Entisols. Entisols are recently formed soils with little to no horizon development. They are common on floodplains, steep slopes, and sandy deposits.
Soil & Planting Advisory: Iron County
Soil Verdict
Iron County is in USDA hardiness zone 4a, a cold climate zone. where winter lows can reach -30°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
Iron County is somewhat cooler than the Wisconsin statewide average. The zone range of 4a-4b within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Iron 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.