Webb County Soil Data
Webb County, Texas
Avg pH
7.4
Texture
Loam
Drainage
N/A
Organic Matter
1.2%
Hydrologic Group
D
Data Story
About Soil in Webb County, Texas
Alkaline Soils of the South Texas Plain
Webb County’s soil is moderately alkaline with an average pH of 7.43. This value is higher than both the national median of 6.5 and the state average of 7.09. The overall soil score of 18.8 reflects the challenges of farming in this semi-arid region.
Loamy Sand and Silt Mix
The soil consists of 47.6% sand, 24.8% silt, and 22.4% clay. This mixture provides a relatively balanced texture, though the high sand content remains the dominant factor. It offers moderate workability but requires careful management to prevent moisture loss.
Low Organic Matter and Moisture Storage
Organic matter content is quite low at 1.15%, significantly trailing the Texas average of 1.66%. The available water capacity of 0.122 in/in is also below the state average of 0.133. For successful growth, supplemental fertilization and irrigation are almost always necessary.
Slow Infiltration and Runoff Concerns
The county’s soils belong to Hydrologic Group D, characterized by very slow infiltration rates. This means that despite the sandy surface, water does not move easily through the profile. Rapid runoff is common during the intense, short-duration rains typical of South Texas.
Heat-Tolerant Gardening in Zone 9b
Hardiness Zone 9b means very mild winters and intense summer heat for Webb County. Plants that thrive here must be extremely heat-tolerant and able to handle alkaline soil conditions. Native species like Texas Sage and Mesquite are perfectly adapted to these specific soil constraints.
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
Drainage class data not available.
Soil Profile
Dominant texture: Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does Webb County have?
Webb County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 48% sand, 25% silt, and 22% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Webb County's soil acidic or alkaline?
Webb County's soil has a pH of 7.4, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Webb County?
Drainage class data is not currently available for Webb County.
What crops or plants grow well in Webb County's soil?
Based on Webb County's Loam texture, pH of 7.4, and drainage class, the soil is well suited for drought-tolerant crops and native grasses, row crops and vegetable gardens.
What USDA soil order is found in Webb County?
The dominant USDA soil order for Webb County is not currently available in our dataset.
Planning your lawn? View lawn care data for Webb County on LawnByCounty.com →
Other Counties in Texas
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.