St. Charles County Soil Data

St. Charles County, Missouri

Avg pH

6.5

Texture

Silty clay loam

Drainage

Well drained

Organic Matter

2.3%

Hydrologic Group

C

Data Story

About Soil in St. Charles County, Missouri

Near-Perfect pH for Versatile Farming

St. Charles County features an average pH of 6.53, which sits precisely at the national median for optimal nutrient availability. These Entisols provide a young but productive foundation, achieving a total soil score of 70.9.

Mastering Silty Clay Loams

The dominant silty clay loam texture comes from a mix of 61.9% silt and 21.6% clay. This composition ensures a fine-textured soil that holds moisture better than the 16% sand component would suggest.

Steady Nutrients and Strong Hydration

With 2.34% organic matter, these soils are healthier than the national average but fall below the state’s high organic benchmark of 4.74%. The available water capacity of 0.194 in/in remains superior to the Missouri average of 0.183.

Well Drained for Diverse Use

The land is officially well drained, making it suitable for both intensive agriculture and residential construction. It belongs to hydrologic group C, meaning it has a slow rate of water transmission when thoroughly wet.

Garden Success in Zone 6b

Zone 6b allows for a long growing season that supports everything from leafy greens to fruit trees. These well-drained silty soils provide a perfect environment for gardeners to maximize their harvest.

Soil Composition

Silty clay loam
Sand: 16.0%
Silt: 61.9%
Clay: 21.6%
Silty clay loam

Soil pH

6.5pH
6.52772633430889
Strongly AcidicSlightly AcidicNeutralSlightly AlkalineStrongly Alkaline
Ideal lawn range: 6.0 - 7.0

Soil Series

Detailed soil series data not yet available for this county.

Hydrologic Group

Group C — Moderate-High Runoff

Soils with slow infiltration rates, often with a layer that impedes downward water movement. Higher clay content restricts drainage.

Runoff potential:Moderate-High

Drainage Class

Well drained

Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.

Soil Profile

Dominant texture: Silty clay loam

O HorizonOrganic layer
0-2"
A HorizonTopsoil
2-10"
B HorizonSubsoil
10-30"
C HorizonParent material
30-60"
R HorizonBedrock
60"+

Typical soil profile. Actual depths vary by location.

Frequently Asked Questions

What type of soil does St. Charles County have?

St. Charles County's soil is classified as Silty clay loam. This indicates the relative proportions of sand, silt, and clay — 16% sand, 62% silt, and 22% clay. Loamy soils hold moisture well and support a wide range of plants.

Is St. Charles County's soil acidic or alkaline?

St. Charles County's soil has a pH of 6.5, which is near neutral. This range is ideal for most garden plants and field crops.

What is the drainage class for St. Charles County?

St. Charles County has a dominant drainage class of "Well drained." Well-drained soils allow excess water to move through quickly, reducing waterlogging risk and supporting most field and garden crops.

What crops or plants grow well in St. Charles County's soil?

Based on St. Charles County's Silty clay loam texture, pH of 6.5, and Well drained, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens, most annual and perennial crops.

What USDA soil order is found in St. Charles County?

St. Charles County's dominant soil order is Entisols. Entisols are recently formed soils with little to no horizon development. They are common on floodplains, steep slopes, and sandy deposits.

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.