Williamson County Soil Data
Williamson County, Tennessee
Avg pH
5.6
Texture
Silty clay loam
Drainage
Well drained
Organic Matter
1.8%
Hydrologic Group
D
Data Story
About Soil in Williamson County, Tennessee
Williamson's Dark, Productive Mollisols
Williamson County features Mollisols, the same soil order that powers the American Breadbasket. With a pH of 5.59, these soils are less acidic than the Tennessee average of 5.35, though still below the national 6.5 median. This silty clay loam provides a high-quality foundation for both landscaping and agriculture.
Balanced Clay and Silt Mix
The soil contains 23.9% clay and 54.3% silt, giving it a heavier silty clay loam texture. While the 18.9% sand content is low, the structure provides excellent nutrient holding capacity. This mix creates a sturdy soil that supports vigorous plant growth but can be heavy to till.
Classic Fertility and Moisture Stats
Organic matter sits at 1.78%, which is lower than the state average of 2.44% but typical for developed areas. The available water capacity of 0.165 in/in is just shy of the state norm. These levels suggest that while the soil is naturally productive, it benefits significantly from mulching and organic amendments.
Excellent Drainage with Runoff Risks
The soil is classified as well drained, which is superior to many neighboring counties. However, its hydrologic group D rating warns that infiltration can be slow once the soil is saturated, leading to high runoff. This combination makes it excellent for most plants, provided the terrain allows for water movement.
Prime Gardening in Zone 7b
Williamson's Mollisols are legendary for supporting lush pastures and diverse home gardens. The well-drained nature of the soil makes it ideal for fruit trees and perennial shrubs that dislike 'wet feet.' Take advantage of some of the state's best-drained soil and start your planting project today.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group D — High Runoff
Clay soils with very slow infiltration rates. Highest runoff potential. These soils have a permanent high water table or are shallow over impervious material.
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
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does Williamson County have?
Williamson County's soil is classified as Silty clay loam. This indicates the relative proportions of sand, silt, and clay — 19% sand, 54% silt, and 24% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Williamson County's soil acidic or alkaline?
Williamson County's soil has a pH of 5.6, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Williamson County?
Williamson 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 Williamson County's soil?
Based on Williamson County's Silty clay loam texture, pH of 5.6, 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 Williamson County?
Williamson County's dominant soil order is Mollisols. Mollisols are fertile, dark-colored soils that formed under grassland vegetation. They are among the most productive agricultural soils in the world.
Planning your lawn? View lawn care data for Williamson County on LawnByCounty.com →
Other Counties in Tennessee
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.