McMullen County Soil Data
McMullen County, Texas
Avg pH
7.5
Texture
Water
Drainage
N/A
Organic Matter
1.8%
Hydrologic Group
D
Data Story
About Soil in McMullen County, Texas
Alkaline Terrain of the Brush Country
McMullen County features an average pH of 7.48, making it more alkaline than the national 6.5 median. The dominant surface classification in this dataset is 'water,' highlighting the importance of the Frio River and local reservoirs on the landscape. The terrestrial soils are typically basic and rich in minerals.
High Sand and Clay Content
The soil composition is a mix of 44.0% sand and 28.8% clay, with silt making up the remaining 23.7%. This combination can create a 'heavy' feel that holds water well but may become compacted under pressure. The relatively high sand content helps provide some necessary aeration for plant roots.
Solid Fertility and Water Storage
Organic matter stands at 1.82%, which is higher than the Texas average of 1.66%. The available water capacity is also strong at 0.134 in/in, sitting just above the state benchmark. These levels support the dense brush and ranch land that the county is famous for.
Runoff Challenges in Group D
Most soils in this county fall into hydrologic group D, which means they have a high runoff potential and slow infiltration. This makes the landscape prone to flash flooding during rare but heavy rain events. Land management here requires careful attention to erosion and water catchment.
Tough and Tropical in Zone 9b
Located in the warm 9b hardiness zone, McMullen County can support citrus and other semi-tropical plants if irrigated. Native species like mesquite and prickly pear thrive in this alkaline, high-runoff environment. Focus on drought-tolerant landscaping to create a beautiful and sustainable outdoor space.
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: Water
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does McMullen County have?
McMullen County's soil is classified as Water. This indicates the relative proportions of sand, silt, and clay — 44% sand, 24% silt, and 29% clay. Sandy soils drain quickly but may need more frequent irrigation and fertilization.
Is McMullen County's soil acidic or alkaline?
McMullen County's soil has a pH of 7.5, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for McMullen County?
Drainage class data is not currently available for McMullen County.
What crops or plants grow well in McMullen County's soil?
Based on McMullen County's Water texture, pH of 7.5, and drainage class, the soil is well suited for drought-tolerant crops and native grasses.
What USDA soil order is found in McMullen County?
The dominant USDA soil order for McMullen County is not currently available in our dataset.
Planning your lawn? View lawn care data for McMullen 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.