Fannin County Soil Data
Fannin County, Texas
Avg pH
7.0
Texture
Clay
Drainage
Well drained
Organic Matter
1.5%
Hydrologic Group
D
Data Story
About Soil in Fannin County, Texas
The Heavy Vertisols of Fannin County
Fannin County is dominated by Vertisols, which are known for their high clay content and ability to shrink and swell. The average pH of 6.99 is nearly neutral, sitting right between the national median of 6.5 and the state average of 7.09.
A Dense Clay-Heavy Foundation
The soil composition includes 28.3% clay and 37.2% silt, creating a heavy texture that can be difficult to till when wet. While the 34.5% sand helps slightly with aeration, the overall mix is designed for high nutrient retention. This composition requires patience from farmers waiting for the right moisture levels.
Superior Moisture Retention for Crops
Available water capacity reaches 0.158 in/in, significantly higher than the Texas average of 0.133. Though organic matter is slightly low at 1.51%, the soil's ability to hold water makes it highly productive. This translates to a strong soil score of 40.8, well above the state benchmark.
Managing the Challenge of Group D Soils
The county is generally well drained, but the hydrologic group D classification warns of very slow infiltration rates. Heavy rains can lead to rapid runoff because the clay particles pack tightly together. Builders should account for significant soil expansion and contraction when designing foundations.
Success in Hardiness Zone 8a
The neutral pH and high water capacity support a wide range of crops from wheat to sturdy garden perennials. Zone 8a provides a long growing season that benefits from the soil's natural ability to store moisture. Use organic mulch to help keep the heavy clay soils from crusting over in the summer heat.
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
Well drained
Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.
Soil Profile
Dominant texture: Clay
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does Fannin County have?
Fannin County's soil is classified as Clay. This indicates the relative proportions of sand, silt, and clay — 34% sand, 37% silt, and 28% clay. Clay soils retain water and nutrients but can have drainage challenges.
Is Fannin County's soil acidic or alkaline?
Fannin County's soil has a pH of 7.0, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Fannin County?
Fannin 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 Fannin County's soil?
Based on Fannin County's Clay texture, pH of 7.0, and Well drained, the soil is well suited for vegetables, grains, and most field crops, wetland plants and crops tolerant of slow drainage, most annual and perennial crops.
What USDA soil order is found in Fannin County?
Fannin County's dominant soil order is Vertisols. Vertisols are clay-rich soils that shrink and crack when dry and swell when wet. They are challenging to manage but often fertile.
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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.