Grady County Soil Data
Grady County, Oklahoma
USDA SSURGO / PHZMAvg pH
6.0
Texture
Water
Drainage
N/A
Organic Matter
1.6%
Hydrologic Group
D
Data Story
About Soil in Grady County, Oklahoma
A Higher Standard for Grady Soils
Grady County earns a soil score of 40.8, outperforming the state average of 35.3. The average pH of 6.01 is slightly acidic compared to the national 6.5 median but aligns well with typical Oklahoma profiles. This balanced acidity supports a wide range of regional vegetation and agricultural activity.
Sand-Driven Texture for Easy Workability
The soil composition features a high sand content of 44.1% paired with 34.0% silt and 15.1% clay. This relatively low clay percentage makes the soil easier to plow and manage throughout the year. The higher silt and sand ratios provide a structure that resists the heavy clumping seen in clay-dominant regions.
Superior Water Retention Capabilities
With an available water capacity of 0.153 in/in, Grady County exceeds the state average of 0.144 in/in. Organic matter levels reach 1.58%, which is higher than some neighbors but still below the national 2.0% benchmark. This combination indicates a resilient soil that keeps plants hydrated during dry spells.
Managing High Runoff Potential
Classified under Hydrologic Group D, these soils naturally resist rapid water infiltration. This classification suggests that during heavy Oklahoma storms, water is more likely to run off the surface than soak in immediately. Site planners must prioritize drainage solutions to prevent erosion and surface saturation.
Thriving in the 7b Heartlands
The 7b hardiness zone allows for a diverse palette of tomatoes, peppers, and hardy perennials. The soil's above-average water capacity makes it an excellent choice for consistent garden yields. Residents can leverage the strong soil score to build robust backyard vegetable plots.
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
Soil Amendment Products
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Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Grady County have?
Grady County's soil is classified as Water. This indicates the relative proportions of sand, silt, and clay — 44% sand, 34% silt, and 15% clay. Sandy soils drain quickly but may need more frequent irrigation and fertilization.
Is Grady County's soil acidic or alkaline?
Grady County's soil has a pH of 6.0, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Grady County?
Drainage class data is not currently available for Grady County.
What crops or plants grow well in Grady County's soil?
Based on Grady County's Water texture, pH of 6.0, and drainage class, the soil is well suited for vegetables, grains, and most field crops.
What USDA soil order is found in Grady County?
The dominant USDA soil order for Grady County is not currently available in our dataset.
Soil & Planting Advisory: Grady County
Soil Verdict
Grady 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
Grady County closely matches the Oklahoma average hardiness conditions.
Planning your lawn? View lawn care data for Grady County on LawnByCounty.com →
Other Counties in Oklahoma
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.