Washington County Soil Data

Washington County, Tennessee

Avg pH

5.1

Texture

Silt loam

Drainage

Moderately well drained

Organic Matter

5.4%

Hydrologic Group

C

Data Story

About Soil in Washington County, Tennessee

Washington's Strongly Acidic Inceptisols

Washington County features a silt loam texture within the Inceptisol order, indicating relatively young soil development. At a pH of 5.06, these soils are significantly more acidic than the state average of 5.35. This sharp deviation from the national 6.5 median requires active intervention for traditional agriculture.

Silt-Driven Texture and Drainage

With 40.8% silt and 31.2% sand, these soils prioritize air space and drainage over heavy structure. The relatively low clay content of 18.0% helps prevent the soil from becoming overly compacted during wet seasons. This mix provides a smooth, workable surface for tilling and planting.

Exceptional Organic Richness

The county boasts a high organic matter content of 5.43%, more than doubling the Tennessee average of 2.44%. Despite an available water capacity of 0.155 in/in being below the state norm, the high organic content provides a massive natural nutrient boost. This profile makes it one of the most naturally enriched soils in the region.

Moderate Drainage for Silt Loams

Classified as moderately well drained, these soils belong to hydrologic group C, indicating somewhat slow infiltration rates. While the silt loam texture feels light, the subsurface can hold water after heavy storms. This requires careful consideration when planning septic systems or large-scale drainage projects.

Thriving in Washington's Zone 7b

The high organic matter in zone 7b is perfect for growing nutrient-hungry greens and root vegetables. Blueberries and other acid-loving shrubs will love the 5.06 pH right out of the box. Grab a spade and take advantage of this unusually rich organic foundation to start your home garden.

Soil Composition

Silt loam
Sand: 31.2%
Silt: 40.8%
Clay: 18.0%
Silt loam

Soil pH

5.1pH
5.06055111547601
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

Moderately well drained

Water is removed somewhat slowly. May have a slowly permeable layer or seasonal water table.

Soil Profile

Dominant texture: Silt 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 Washington County have?

Washington County's soil is classified as Silt loam. This indicates the relative proportions of sand, silt, and clay — 31% sand, 41% silt, and 18% clay. Loamy soils hold moisture well and support a wide range of plants.

Is Washington County's soil acidic or alkaline?

Washington 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 Washington County?

Washington County has a dominant drainage class of "Moderately 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 Washington County's soil?

Based on Washington County's Silt loam texture, pH of 5.1, and Moderately well drained, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens, most annual and perennial crops.

What USDA soil order is found in Washington County?

Washington County's dominant soil order is Inceptisols. Inceptisols are young soils with weak horizon development. They occur in a wide range of climates and parent materials.

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.