Soil series profile

Wilson soil series

Wilson is a moderately well drained soil with a silt loam surface, mapped on 891,289 acres in 62 counties across 2 states. Hydrologic group D.

#224 by mapped area fine Oxyaquic Vertic Haplustalfs (Alfisols)

Drainage class
Moderately well drained
100% of mapped acres
Hydrologic group
D
68% of mapped acres
Typical topsoil pH
6.5
slightly acidic · range 6.5–6.5
Mapped area
891k
acres in 62 counties, 2 states

Typical Wilson profile

Texture and pH by depth

Typical Wilson soil profile by depth 0 in 20 in 40 in 60 in 0–7 in · Ap · pH 6.5 · 23% clay Silt loam 7–31 in · Btss · pH 6.7 · 43% clay Clay 31–36 in · Btkss · pH 6.7 · 43% clay Clay 36–42 in · Btkssyg · pH 7.8 · 48% clay Clay 42–80 in · Btkyg · pH 7.5 · 38% clay Clay loam
Depth to scale. More strongly shaded layers hold more clay. Horizon names are the soil survey's (A = topsoil, B = subsoil, C = parent material).
Show as a table
Typical Wilson horizons (representative values)
Depth Texture pH Clay Sand Organic matter
0–7 in (Ap) Silt loam 6.5 23% 25% 1.25%
7–31 in (Btss) Clay 6.7 43% 28% 1%
31–36 in (Btkss) Clay 6.7 43% 28% 0.5%
36–42 in (Btkssyg) Clay 7.8 48% 14% 0.5%
42–80 in (Btkyg) Clay loam 7.5 38% 25% 0.5%

Representative values from the most extensive Wilson map unit (Wilson silt loam, 0 to 1 percent slopes, survey area TX231). Other map units of this series vary within the series range.

Hands holding dark garden soil
Stock photo for illustration, not a sample of this soil series. Credit on the Sources & method page.

What this means

What Wilson soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Wilson soils is slightly acidic: pH 6.5, the range most vegetables, flowers and lawn grasses prefer.

Loamy topsoil (loam, silt loam and similar) covers 88% of mapped Wilson acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is clay loam (41% of mapped Wilson acres).

100% of mapped Wilson acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On >99% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.

For a septic system

For conventional septic absorption fields, NRCS rates 88% of the acres in mapped Wilson soils very limited, 0% somewhat limited and 0% not limited (12% not rated, such as urban land, pits or water).

Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.

Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.

Generated from the mapped numbers above using fixed rules, not a site visit. See how these notes are written.

Where Wilson soil is found

Mapped acres

Wilson is mapped in Texas and Oklahoma. The 60 counties with the most Wilson acres:

Counties with the most mapped Wilson soil
County Acres Share of county land
Falls County, TX 98,899 20.1%
Navarro County, TX 75,287 11.6%
Kaufman County, TX 57,032 11.4%
Hunt County, TX 55,372 10.3%
Limestone County, TX 48,343 8.3%
Grayson County, TX 45,320 7.6%
Milam County, TX 40,221 6.2%
McLennan County, TX 36,792 5.5%
Fannin County, TX 30,748 5.4%
Lamar County, TX 30,486 5.2%
Ellis County, TX 27,897 4.6%
Delta County, TX 23,515 14.2%
Bastrop County, TX 22,940 4.0%
Denton County, TX 21,783 3.8%
Hill County, TX 20,155 3.3%
Cooke County, TX 19,141 3.4%
Hopkins County, TX 16,850 3.4%
Collin County, TX 14,946 2.8%
Dallas County, TX 14,023 2.5%
DeWitt County, TX 12,141 2.1%
Carter County, OK 10,826 2.1%
Caldwell County, TX 10,745 3.1%
Bell County, TX 10,399 1.5%
Fayette County, TX 9,830 1.6%
Van Zandt County, TX 9,787 1.8%
Williamson County, TX 9,058 1.3%
Gonzales County, TX 7,435 1.1%
Robertson County, TX 7,208 1.3%
Tarrant County, TX 7,008 1.3%
Travis County, TX 6,644 1.0%
Johnston County, OK 6,500 1.6%
Burleson County, TX 6,411 1.5%
Washington County, TX 5,941 1.5%
Austin County, TX 5,893 1.4%
Colorado County, TX 5,786 0.9%
Brazos County, TX 5,554 1.5%
Rockwall County, TX 5,362 6.6%
Rains County, TX 5,069 3.4%
Lee County, TX 4,245 1.1%
Johnson County, TX 4,171 0.9%
Freestone County, TX 4,121 0.7%
Leon County, TX 4,101 0.6%
Red River County, TX 3,466 0.5%
Guadalupe County, TX 3,189 0.7%
Coal County, OK 2,969 0.9%
Grimes County, TX 2,644 0.5%
Henderson County, TX 2,492 0.4%
Bryan County, OK 1,984 0.3%
Love County, OK 1,796 0.5%
Marshall County, OK 1,677 0.7%
Madison County, TX 1,390 0.5%
Franklin County, TX 1,281 0.7%
Garvin County, OK 1,240 0.2%
Anderson County, TX 963 0.1%
Murray County, OK 801 0.3%
Lavaca County, TX 597 0.1%
Waller County, TX 296 0.1%
Montgomery County, TX 170 0.0%
Bexar County, TX 156 0.0%
Choctaw County, OK 84 0.0%

Septic absorption fields

NRCS rating, share of Wilson acres

Not limited 0%
Somewhat limited 0%
Very limited 88%
Not rated 12%
Septic tank absorption field rating across mapped Wilson acres. Scale 0 to 100% of mapped land.
Show as a table
Septic tank absorption field rating across mapped Wilson acres.
CategoryShare of acres
Not limited0.0%
Somewhat limited0.0%
Very limited88.1%
Not rated11.9%

Drainage, water table and flooding

Share of Wilson acres

Depth to seasonal high water table
About 0 inches (median where reported); within 18 inches on 11% of acres.
Flooding
Not mapped as flooding on most acres.
Slope
Typically 0–2% (median 1%).
Topsoil organic matter
Median 1.2%.

Drainage class

Excessively drained 0%
Somewhat excessively drained 0%
Well drained 0%
Moderately well drained 100%
Somewhat poorly drained 0%
Poorly drained 0%
Very poorly drained 0%
Drainage class across mapped Wilson acres. Scale 0 to 100% of mapped land.
Show as a table
Drainage class across mapped Wilson acres.
CategoryShare of acres
Excessively drained0.0%
Somewhat excessively drained0.0%
Well drained0.0%
Moderately well drained100.0%
Somewhat poorly drained0.0%
Poorly drained0.0%
Very poorly drained0.0%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%
B: moderate infiltration 0%
C: slow infiltration 21%
D: very slow infiltration (clayey, shallow or wet) 68%
A/D: D as is, A if drained 0%
B/D: D as is, B if drained 0%
C/D: D as is, C if drained 11%
Not rated <1%
Hydrologic soil group across mapped Wilson acres. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group across mapped Wilson acres.
CategoryShare of acres
A: fast infiltration (mostly sandy or gravelly)0.0%
B: moderate infiltration0.0%
C: slow infiltration20.5%
D: very slow infiltration (clayey, shallow or wet)68.0%
A/D: D as is, A if drained0.0%
B/D: D as is, B if drained0.0%
C/D: D as is, C if drained11.2%
Not rated0.3%

Sources & data dates

Source
USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
Data date
SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
Scope
All map unit components named Wilson (component kind "Series") in SSURGO: 891,289 acres.
Method
Shares are by mapped acres of Wilson components. The profile comes from the single largest Wilson component. Full methodology.

Independent reference site. No government affiliation or endorsement.

Full narrative description: USDA Official Soil Series Description for Wilson.