St. Clair County Soil Data
St. Clair County, Alabama
Avg pH
5.1
Texture
Loam
Drainage
N/A
Organic Matter
1.4%
Hydrologic Group
N/A
Data Story
About Soil in St. Clair County, Alabama
Woodland acidity levels require careful management
With a pH of 5.11, St. Clair County soil is more acidic than both the state average of 5.21 and the national median of 6.5. This low pH profile is characteristic of many Alabama woodlands and requires management for most row crops.
Balanced blend of sand and silt
The composition consists of 44.8% sand, 36.2% silt, and 19.0% clay. This blend creates a versatile soil structure that balances the drainage of sand with the structural stability of clay.
Strong moisture retention despite low fertility
Organic matter sits at 1.41%, which is roughly 19% lower than the state average of 1.74%. Despite this, the soil maintains an impressive available water capacity of 0.155 in/in, outperforming the state baseline of 0.138.
Soil structure prevents heavy compaction
While specific drainage classes are not recorded, the balanced sand and silt levels suggest moderate infiltration rates. This mix typically prevents the heavy compaction often found in counties with higher clay percentages.
Long growing seasons for leafy greens
Gardeners in Hardiness Zone 8a can take advantage of a robust growing season for brassicas and leafy greens. Adding organic amendments will help bridge the gap between the current fertility and the national 2.0% organic matter benchmark.
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
Frequently Asked Questions
What type of soil does St. Clair County have?
St. Clair County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 45% sand, 36% silt, and 19% clay. Loamy soils hold moisture well and support a wide range of plants.
Is St. Clair County's soil acidic or alkaline?
St. Clair County's soil has a low pH of 5.1, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for St. Clair County?
Drainage class data is not currently available for St. Clair County.
What crops or plants grow well in St. Clair County's soil?
Based on St. Clair County's Loam texture, pH of 5.1, and drainage class, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens.
What USDA soil order is found in St. Clair County?
The dominant USDA soil order for St. Clair County is not currently available in our dataset.
Planning your lawn? View lawn care data for St. Clair County on LawnByCounty.com →
Other Counties in Alabama
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.