Soil series profile
Ferris soil series
Ferris is a well drained soil with a clay surface, mapped on 474,347 acres in 41 counties across 2 states. Hydrologic group D.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- D 100% of mapped acres
- Typical topsoil pH
- 8.2 moderately alkaline · range 8.2–8.2
- Mapped area
- 474k acres in 41 counties, 2 states
Typical Ferris profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–10 in (Ap) | Clay | 8.2 | 52% | 19% | 1.3% |
| 10–30 in (Bkss1) | Clay | 8.2 | 53% | 18% | 0.5% |
| 30–45 in (Bkss2) | Clay | 8.2 | 53% | 18% | 0.4% |
| 45–60 in (Cdk) | Clay | 8.2 | 58% | 16% | 0.1% |
What this means
What Ferris soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Ferris soils is moderately alkaline: pH 8.2. Acid-loving plants such as blueberries and azaleas struggle without amended beds, and some trees and shrubs show iron chlorosis (yellow leaves with green veins).
Clayey topsoil covers 86% of mapped Ferris acres. Clay holds water and nutrients but drains slowly and compacts if worked wet: add compost, avoid tilling soggy soil and consider raised beds. The most common surface texture is clay (86% of mapped Ferris acres).
100% of mapped Ferris acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 100% 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 86% of the acres in mapped Ferris soils very limited, 0% somewhat limited and 0% not limited (15% 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.
Where Ferris soil is found
Mapped acres
Ferris is mapped in Texas and Oklahoma.
| County | Acres | Share of county land |
|---|---|---|
| Hill County, TX | 55,463 | 9.1% |
| Limestone County, TX | 30,214 | 5.2% |
| Marshall County, OK | 29,712 | 12.6% |
| Hunt County, TX | 26,426 | 4.9% |
| Fannin County, TX | 26,285 | 4.6% |
| Dallas County, TX | 23,790 | 4.2% |
| Navarro County, TX | 20,194 | 3.1% |
| Walker County, TX | 19,431 | 3.9% |
| Bryan County, OK | 19,410 | 3.4% |
| Lamar County, TX | 17,122 | 2.9% |
| Kaufman County, TX | 17,032 | 3.4% |
| Ellis County, TX | 16,714 | 2.8% |
| Collin County, TX | 14,636 | 2.7% |
| Milam County, TX | 14,544 | 2.3% |
| Bell County, TX | 12,802 | 1.9% |
| Williamson County, TX | 12,156 | 1.7% |
| Travis County, TX | 11,747 | 1.8% |
| Johnson County, TX | 10,454 | 2.2% |
| McLennan County, TX | 10,385 | 1.6% |
| Red River County, TX | 10,208 | 1.5% |
| Falls County, TX | 9,394 | 1.9% |
| Guadalupe County, TX | 7,476 | 1.6% |
| Rockwall County, TX | 7,251 | 8.9% |
| Choctaw County, OK | 6,983 | 1.4% |
| Denton County, TX | 6,778 | 1.2% |
| Bastrop County, TX | 6,429 | 1.1% |
| Caldwell County, TX | 4,842 | 1.4% |
| Johnston County, OK | 4,171 | 1.0% |
| Hopkins County, TX | 3,594 | 0.7% |
| Tarrant County, TX | 3,249 | 0.6% |
| Delta County, TX | 2,919 | 1.8% |
| Comal County, TX | 2,838 | 0.7% |
| Bexar County, TX | 2,189 | 0.3% |
| Grayson County, TX | 1,629 | 0.3% |
| DeWitt County, TX | 1,479 | 0.3% |
| Hays County, TX | 1,159 | 0.3% |
| Henderson County, TX | 1,029 | 0.2% |
| Anderson County, TX | 935 | 0.1% |
| Freestone County, TX | 742 | 0.1% |
| Leon County, TX | 432 | 0.1% |
| Rains County, TX | 102 | 0.1% |
Septic absorption fields
NRCS rating, share of Ferris acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 85.5% |
| Not rated | 14.5% |
Drainage, water table and flooding
Share of Ferris acres
- Depth to seasonal high water table
- None reported within about 6.5 feet (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 4–13% (median 7%).
- Topsoil organic matter
- Median 1.2%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 100.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 0.0% |
| C: slow infiltration | 0.0% |
| D: very slow infiltration (clayey, shallow or wet) | 100.0% |
| A/D: D as is, A if drained | 0.0% |
| B/D: D as is, B if drained | 0.0% |
| C/D: D as is, C if drained | 0.0% |
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 Ferris (component kind "Series") in SSURGO: 474,347 acres.
- Method
- Shares are by mapped acres of Ferris components. The profile comes from the single largest Ferris component. Full methodology.