Grainger County Soil Data
Grainger County, Tennessee
Avg pH
5.2
Texture
Gravelly loam
Drainage
Somewhat excessively drained
Organic Matter
6.5%
Hydrologic Group
B
Data Story
About Soil in Grainger County, Tennessee
Diverse Inceptisols with High Acidity
Grainger County is defined by its Inceptisols and a gravelly loam texture that creates a unique growing environment. The average pH is 5.18, making it more acidic than the state average of 5.35 and well below the national median of 6.5. This sharp acidity requires significant lime for growers wishing to plant standard garden vegetables.
Gravelly Loam with High Sand Content
This soil contains 32.6% sand and 41.5% silt, which is a higher sand percentage than many surrounding counties. The 18.4% clay content is relatively low, contributing to a gravelly loam texture that is easy to work but dries out quickly. This physical structure is ideal for plants that require excellent aeration around their roots.
Rich Organic Matter but Low Water Storage
Grainger County boasts an impressive 6.47% organic matter, nearly triple the state average of 2.44%. Despite this richness, the available water capacity is low at 0.146 in/in, likely due to its gravelly nature. Your soil is fertile and nutrient-dense, but you will need to water more frequently during dry spells.
Excessive Drainage in Hydrologic Group B
The soil is classified as somewhat excessively drained, meaning water moves through the profile very rapidly. As part of hydrologic group B, it transmits water at a moderate-to-fast rate, preventing saturation but increasing the risk of drought stress. This makes the county well-suited for building but challenging for water-hungry crops.
The Home of Famous Tomatoes
Grainger County's Zone 7b climate and well-drained, organic-rich soil are legendary for producing high-quality tomatoes. Peaches and other stone fruits also thrive in these gravelly, well-aerated conditions. Leverage the high organic matter and start your garden with confidence this spring.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group B — Moderate Runoff
Moderately deep, moderately well-drained soils with moderate infiltration rates. Good balance of drainage and water retention.
Drainage Class
Somewhat excessively drained
Water is removed rapidly. Soils may be droughty and have limited water-holding capacity.
Soil Profile
Dominant texture: Gravelly loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does Grainger County have?
Grainger County's soil is classified as Gravelly loam. This indicates the relative proportions of sand, silt, and clay — 33% sand, 42% silt, and 18% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Grainger County's soil acidic or alkaline?
Grainger County's soil has a low pH of 5.2, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Grainger County?
Grainger County has a dominant drainage class of "Somewhat excessively drained." Moderate drainage allows adequate moisture retention while still permitting excess water to drain over time.
What crops or plants grow well in Grainger County's soil?
Based on Grainger County's Gravelly loam texture, pH of 5.2, and Somewhat excessively drained, 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 Grainger County?
Grainger 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.
Planning your lawn? View lawn care data for Grainger 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.