Jefferson County Soil Data
Jefferson County, Kentucky
USDA SSURGO / PHZMAvg pH
5.9
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.1%
Hydrologic Group
N/A
Data Story
About Soil in Jefferson County, Kentucky
Urban Soil Profile
Jefferson County holds a soil score of 57.0, resting right near the state average of 56.2. The average pH is 5.88, which is slightly more acidic than the national median of 6.5 but typical for the Louisville region.
Balanced Urban Texture
The soil contains 62.7% silt, 18.9% clay, and 18.4% sand. This relatively balanced mix provides the workability needed for landscaping while maintaining enough clay to hold onto essential plant nutrients.
Stable Water Availability
Organic matter is 2.08%, meeting the national average but falling below the Kentucky average of 3.55%. However, the available water capacity of 0.194 in/in is quite high, helping urban gardens survive the city's heat-island effects.
Hydrology in the City
Specific drainage classes are not listed, but the high silt content can lead to slow infiltration in urban settings. Homeowners should ensure their properties have clear drainage paths to manage heavy rain runoff effectively.
Growing in Zone 7a
Located in zone 7a, Jefferson County gardeners can enjoy a long season of peppers, tomatoes, and ornamental flowers. The reliable water capacity makes this an excellent place for raised-bed gardening or community plots.
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: Silt Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 5.9. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Jefferson County have?
Jefferson County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 18% sand, 63% silt, and 19% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Jefferson County's soil acidic or alkaline?
Jefferson County's soil has a pH of 5.9, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Jefferson County?
Drainage class data is not currently available for Jefferson County.
What crops or plants grow well in Jefferson County's soil?
Based on Jefferson County's Silt Loam texture, pH of 5.9, and drainage class, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens.
What USDA soil order is found in Jefferson County?
The dominant USDA soil order for Jefferson County is not currently available in our dataset.
Soil & Planting Advisory: Jefferson County
Soil Verdict
Jefferson County is in USDA hardiness zone 7a, a moderate climate zone. where winter lows can reach 0°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. Winter protection (mulch, burlap wraps) helps push the zone boundary for desired species. 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. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
Jefferson County closely matches the Kentucky average hardiness conditions.
Planning your lawn? View lawn care data for Jefferson County on LawnByCounty.com →
Other Counties in Kentucky
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.