Coles County Soil Data
Coles County, Illinois
USDA SSURGO / PHZMAvg pH
6.6
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.7%
Hydrologic Group
N/A
Data Story
About Soil in Coles County, Illinois
Balanced and Productive Coles County Soil
Coles County soil has an average pH of 6.56, making it slightly more alkaline than the Illinois average and very close to the national median of 6.5. This near-perfect pH balance supports a diverse range of biological activity and nutrient uptake. It is an ideal starting point for both high-yield agriculture and domestic landscaping.
The Silt-Rich Profile of the Prairie
With 64.1% silt and 21.4% clay, Coles County soil is fine-textured and highly retentive. The 14.5% sand content is relatively low, meaning the soil has a heavy feel and significant structural strength. This composition is typical of the productive prairie soils that define the Central Illinois region.
Strong Organic Foundation
Organic matter in Coles County is a healthy 2.69%, significantly higher than the national average of 2.0% but just under the state average of 2.94%. The available water capacity is 0.196 in/in, providing reliable moisture access for crops and gardens. These stats translate to a respectable soil score of 73.7, right in line with the state average.
Moderate Drainage for Diverse Uses
Specific drainage classes are not currently listed, but the silt-heavy mix suggests moderate to slow natural drainage. A water capacity of 0.196 in/in ensures that the soil stays moist without the extreme saturation seen in heavier clay counties. This makes the land generally stable for construction and forgiving for most garden plants.
Vibrant Growing in Zone 6a
Coles County belongs to Zone 6a, a versatile climate for growing everything from sunflowers to sweet corn. The neutral pH of 6.56 means you won't need to struggle with soil acidity to get great results in your garden. It is a fantastic place to plant a diverse array of perennials and vegetables this season.
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 Coles County have?
Coles County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 15% sand, 64% silt, and 21% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Coles County's soil acidic or alkaline?
Coles County's soil has a pH of 6.6, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Coles County?
Drainage class data is not currently available for Coles County.
What crops or plants grow well in Coles County's soil?
Based on Coles County's Silt Loam texture, pH of 6.6, 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 Coles County?
The dominant USDA soil order for Coles County is not currently available in our dataset.
Soil & Planting Advisory: Coles County
Soil Verdict
Coles County is in USDA hardiness zone 6a, a moderate climate zone. where winter lows can reach -10°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. Winter protection (mulch, burlap wraps) helps push the zone boundary for desired species. 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
Coles County closely matches the Illinois average hardiness conditions.
Planning your lawn? View lawn care data for Coles 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.