Iron County Soil Data
Iron County, Michigan
USDA SSURGO / PHZMAvg pH
4.6
Texture
Water
Drainage
N/A
Organic Matter
44.8%
Hydrologic Group
N/A
Data Story
About Soil in Iron County, Michigan
Highly Acidic and Unique Northern Soils
Iron County features an extremely acidic average pH of 4.57, well below both the state average and the national 6.5 median. Despite this acidity, its soil score of 67.2 is the highest in this group, indicating exceptional biological potential.
A Silty, Water-Rich Landscape
The soil is unusually silty at 67.1%, with only 24.6% sand and 5.6% clay. This unique mix creates a smooth, flour-like texture that is highly fertile but can be prone to erosion if not covered by vegetation.
Exceptional Organic Matter Levels
Iron County boasts a massive 44.83% organic matter content, more than double the state average. This is paired with an incredible available water capacity of 0.339 in/in, the highest in the region, meaning the soil acts like a sponge for moisture.
Complex Hydrology and Water Retention
The dominant texture is classified as water-influenced, suggesting many areas consist of peat or wetland margins. While specific drainage classes are unavailable, the high silt and water capacity indicate a landscape that stays damp much longer than sandy neighbors.
Cold-Hardy Gardening in Zone 4a
In the chilly zone 4a, Iron County gardeners should focus on short-season crops like kale, radishes, and peas. The rich, silty soil provides an amazing base for a forest garden or cool-weather vegetable production.
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: Water
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 4.6. 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 Water. This indicates the relative proportions of sand, silt, and clay — 25% sand, 67% silt, and 6% clay. Sandy soils drain quickly but may need more frequent irrigation and fertilization.
Is Iron County's soil acidic or alkaline?
Iron County's soil has a low pH of 4.6, 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?
Drainage class data is not currently available for Iron County.
What crops or plants grow well in Iron County's soil?
Based on Iron County's Water texture, pH of 4.6, and drainage class, the soil is well suited for acid-loving plants like blueberries and azaleas.
What USDA soil order is found in Iron County?
The dominant USDA soil order for Iron County is not currently available in our dataset.
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 Michigan 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 Michigan
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.