Oldham County Soil Data
Oldham County, Texas
USDA SSURGO / PHZMAvg pH
7.6
Texture
Loam
Drainage
Well drained
Organic Matter
1.7%
Hydrologic Group
B
Data Story
About Soil in Oldham County, Texas
Rich Loamy Mollisols
Oldham County is dominated by Mollisols, a soil order known for its deep, fertile surface horizons. The average pH of 7.62 is more alkaline than the national median of 6.5. These loamy soils provide a solid foundation for both ranching and farming across the plains.
The Ideal Loam Mix
The soil composition features 40.8% sand, 32.0% silt, and 25.8% clay, classifying it as a classic loam. This texture allows for excellent root penetration and easy tilling compared to heavier clay soils. It strikes a functional balance between drainage and structural integrity.
Productive Organic Foundations
Organic matter sits at 1.71%, which is slightly higher than the Texas state average of 1.66%. With an available water capacity of 0.147 in/in, the soil holds more moisture than the typical Texas plot. These metrics support consistent plant growth even during dry spells.
Efficient Well-Drained Land
The soil is classified as well-drained and belongs to Hydrologic Group B. This group indicates a moderate infiltration rate when thoroughly wet, reducing the risk of surface runoff. Such characteristics make the land reliable for building and diverse agricultural use.
Hardy Crops for Zone 7a
Hardiness Zone 7a allows for a wide range of hardy vegetables and native prairie grasses. The well-drained loam is perfect for deep-rooted perennials and traditional Panhandle crops like cotton. Local gardeners can find great success by focusing on water-wise landscaping and wind-resistant plants.
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
Well drained
Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.
Soil Profile
Dominant texture: Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Alkaline Soil Detected
Your county's average pH is 7.6. These products help acidify soil for better nutrient uptake.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Oldham County have?
Oldham County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 41% sand, 32% silt, and 26% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Oldham County's soil acidic or alkaline?
Oldham County's soil has a pH of 7.6, which is mildly to moderately alkaline. Sulfur amendments can lower pH if needed.
What is the drainage class for Oldham County?
Oldham County has a dominant drainage class of "Well drained." Well-drained soils allow excess water to move through quickly, reducing waterlogging risk and supporting most field and garden crops.
What crops or plants grow well in Oldham County's soil?
Based on Oldham County's Loam texture, pH of 7.6, and Well drained, the soil is well suited for drought-tolerant crops and native grasses, row crops and vegetable gardens, most annual and perennial crops.
What USDA soil order is found in Oldham County?
Oldham County's dominant soil order is Mollisols. Mollisols are fertile, dark-colored soils that formed under grassland vegetation. They are among the most productive agricultural soils in the world.
Soil & Planting Advisory: Oldham County
Soil Verdict
Oldham 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
Oldham County is somewhat cooler than the Texas statewide average.
Planning your lawn? View lawn care data for Oldham 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.