St. Clair County Soil Data
St. Clair County, Missouri
Avg pH
5.9
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.7%
Hydrologic Group
N/A
Data Story
About Soil in St. Clair County, Missouri
Acidic Profiles in St. Clair
St. Clair County manages a soil score of 56.1, which reflects more challenging conditions than the state average. The average pH of 5.90 is notably acidic compared to the national median of 6.5, often requiring lime treatments for sensitive crops.
Higher Sand and Lower Clay
The soil mix contains 26.6% sand and 52.2% silt, which is sandier than many neighboring counties. With only 19.6% clay, this soil is generally easy to work but may lose nutrients more quickly than heavier soils.
Modest Organic Matter and Water
Organic matter sits at 2.72%, beating the national average but trailing the state's typical levels. The available water capacity of 0.178 in/in is slightly below the state average, meaning crops may feel the heat during Missouri summers.
Unclassified Drainage Dynamics
Standardized data for drainage class and hydrologic groups are currently unavailable for this county. Local observers should monitor how quickly water disappears after heavy rains to determine site-specific drainage needs.
Resilient Planting in Zone 6b
Native prairie grasses and acid-tolerant plants like blueberries can thrive in these conditions. With its 6b hardiness zone, the county offers a reliable window for summer vegetables if you manage the soil's acidity.
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
Frequently Asked Questions
What type of soil does St. Clair County have?
St. Clair County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 27% sand, 52% silt, and 20% 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 pH of 5.9, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
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 Silt Loam texture, pH of 5.9, 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 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 Missouri
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.