Union County Soil Data
Union County, Tennessee
USDA SSURGO / PHZMAvg pH
4.9
Texture
Loam
Drainage
N/A
Organic Matter
1.5%
Hydrologic Group
N/A
Data Story
About Soil in Union County, Tennessee
Acidic Profiles in Union County
Union County features a low average pH of 4.92, making its soil more acidic than the state average of 5.35. This level requires significant amendment for traditional vegetable gardening to reach the national median of 6.5.
Balanced Silt and Clay Foundations
The soil consists of 46.8% silt and 21.1% clay, providing a decent structural foundation. With a sand content of 25.3%, there is enough grit to help with workability, though the overall score remains low for the region.
Low Organic Matter and Moisture
Organic matter is low at 1.52%, falling well behind the state average of 2.44%. The available water capacity of 0.152 in/in is also below the state benchmark, suggesting a need for consistent irrigation and mulching.
Limited Hydrology Data for Local Land
Dominant drainage and hydrologic group data are not available for Union County at this time. Gardeners should observe their land after a heavy rain to check for standing water or rapid erosion before planting.
Improving Your Zone 7b Garden
While Union's soil score of 19.7 is low, it still supports zone 7b favorites like timber and native grasses. With soil building techniques like composting, you can transform these lean soils into a productive home garden.
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: Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 4.9. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Union County have?
Union County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 25% sand, 47% silt, and 21% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Union County's soil acidic or alkaline?
Union County's soil has a low pH of 4.9, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Union County?
Drainage class data is not currently available for Union County.
What crops or plants grow well in Union County's soil?
Based on Union County's Loam texture, pH of 4.9, and drainage class, 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 Union County?
The dominant USDA soil order for Union County is not currently available in our dataset.
Soil & Planting Advisory: Union County
Soil Verdict
Union County is in USDA hardiness zone 7b, a moderate climate zone. where winter lows can reach 5°F. Mild winters mean soil rarely freezes deeply, allowing year-round microbial activity and faster organic matter breakdown.
Planting Guidance
Warm-season crops, citrus relatives, and heat-loving ornamentals do well. Cool-season vegetables should be planted in fall and winter. Always match plant selections to the specific microclimate of your property — low spots, slopes, and wind exposure can shift effective hardiness by half a zone.
Soil Implications
Warm soils accelerate organic matter breakdown, so compost and mulch need replenishing more frequently than in cooler zones. Sandy soils common in warm zones drain quickly; water-retentive amendments like compost or peat help hold moisture.
Regional Context
Union County closely matches the Tennessee average hardiness conditions.
Planning your lawn? View lawn care data for Union 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.