Stephenson County Soil Data
Stephenson County, Illinois
USDA SSURGO / PHZMAvg pH
6.4
Texture
Silt Loam
Drainage
N/A
Organic Matter
3.7%
Hydrologic Group
N/A
Data Story
About Soil in Stephenson County, Illinois
Balanced Acidity in Stephenson Soils
Stephenson County features an average pH of 6.40, sitting just below the national median of 6.5. While local taxonomic data remains unspecified, this slightly acidic profile aligns closely with the Illinois state average of 6.39. This pH level supports a wide range of nutrient availability for local crops.
A Silty Foundation for Northern Growth
The soil contains a heavy 67.5% silt concentration mixed with 22.5% clay and 10.0% sand. This silty dominance creates a smooth, flour-like texture that retains moisture well but requires careful management to avoid surface crusting. The low sand content means the soil stays cool and holds onto fertilizers effectively.
Superior Organic Matter and Water Storage
With an organic matter content of 3.71%, these soils significantly outperform the Illinois state average of 2.94%. The available water capacity of 0.220 in/in also beats the state benchmark of 0.204 in/in. These metrics indicate a highly fertile landscape that can sustain plants even during short dry spells.
Deep Moisture Reserves for Local Farms
While specific drainage classes are not officially recorded here, the high available water capacity suggests excellent internal storage. Gardeners should monitor for slow surface runoff due to the high silt and clay levels. Proper aeration helps maintain the soil's natural structure and productivity.
Hardy Crops for a Zone 5a Climate
In USDA Hardiness Zone 5a, this rich soil is perfect for cool-season vegetables like kale and hardy grains. The exceptional organic matter levels provide a massive head start for any home garden project. Plant your favorite perennials with confidence in this nutrient-dense northern Illinois earth.
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: Silt Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Soil Amendment Products
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Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Stephenson County have?
Stephenson County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 10% sand, 67% silt, and 23% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Stephenson County's soil acidic or alkaline?
Stephenson County's soil has a pH of 6.4, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Stephenson County?
Drainage class data is not currently available for Stephenson County.
What crops or plants grow well in Stephenson County's soil?
Based on Stephenson County's Silt Loam texture, pH of 6.4, 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 Stephenson County?
The dominant USDA soil order for Stephenson County is not currently available in our dataset.
Soil & Planting Advisory: Stephenson County
Soil Verdict
Stephenson County is in USDA hardiness zone 5a, a cold climate zone. where winter lows can reach -20°F. Freeze-thaw cycles are moderate; soil biology slows in winter but recovers reliably in spring, supporting a broad range of plants.
Planting Guidance
A wide plant palette is possible: deciduous trees, most shrubs, cool-season vegetables, and many perennials thrive here. 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
Moderate freeze-thaw cycles naturally aerate the soil but can also cause compaction in clay-heavy areas; annual core aeration is beneficial. Organic matter amendments decompose at a moderate pace — aim for 3-5% organic content for optimal fertility. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
Stephenson County is somewhat cooler than the Illinois statewide average. The zone range of 5a-5b within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Stephenson County on LawnByCounty.com →
Other Counties in Illinois
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.