County soil summary
Soil types in Shelby County, Tennessee
The most widespread soils are Memphis, Grenada and Falaya; the most common drainage class is well drained (34% of the land), and typical topsoil pH is 5.3.
- Well or moderately well drained
- 66% of land · state 85%
- Typical topsoil pH
- 5.3 strongly acidic · state 5.3
- Septic fields very limited
- 84% of land · state 82%
- Subject to flooding
- 42% of land, any frequency · state 15%
Most common soils in Shelby County
Share of mapped land
A county is a patchwork of many soils. These 8 cover 82% of the mapped land; 24 named soil series are mapped here in all.
| Soil | Share of land | Drainage | Topsoil pH |
|---|---|---|---|
| Memphis | 19.8% | Well drained | 5.3 |
| Grenada | 16.7% | Moderately well drained | 5.3 |
| Falaya | 16.0% | Somewhat poorly drained | 5.0 |
| Udorthents, siltyLand type, not a soil series | 10.1% | — | — |
| Waverly | 5.8% | Poorly drained | 5.0 |
| Loring | 5.2% | Moderately well drained | 5.3 |
| Collins | 5.0% | Moderately well drained | 5.0 |
| AdlerGeneral soil group, not a named series | 3.6% | — | — |
What this means
What the soils in Shelby County mean for gardens, lawns and septic systems
For your garden
Typical topsoil in Shelby County is strongly acidic: pH 5.3 (most land between 5.0 and 7.3). Most vegetables and lawn grasses do best around 6.0 to 7.0, so lime is often needed; blueberries, azaleas and rhododendrons like it as it is.
Loamy topsoil (loam, silt loam and similar) covers 92% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (91% of the land).
66% of the land is moderately well to excessively drained, which suits most garden plants.
For your lawn and yard
On 60% of the land, 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.
A seasonal high water table comes within 18 inches of the surface on 25% of the land, often in spring. Basements, sump pumps and lawns in low spots feel it first.
For a septic system
For conventional septic absorption fields, NRCS rates 84% of the land in Shelby County very limited, 14% somewhat limited and 0% not limited (2% not rated, such as urban land, pits or water).
That is close to the state as a whole (82% very limited).
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.
Flooding is mapped on 42% of the land (23% occasional, 18% frequent).
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Drainage
How long the soil stays wet
The most common drainage class is well drained (34%). 66% of the land is moderately well drained or better, compared with 85% across Tennessee.
Show as a table
| Category | Shelby County | Tennessee |
|---|---|---|
| Excessively drained | 0.6% | 2.0% |
| Somewhat excessively drained | 0.0% | 11.6% |
| Well drained | 34.4% | 57.1% |
| Moderately well drained | 30.5% | 14.7% |
| Somewhat poorly drained | 21.4% | 4.5% |
| Poorly drained | 12.6% | 4.2% |
| Very poorly drained | 0.1% | 0.1% |
| Not rated | 0.4% | 5.9% |
Septic absorption fields
NRCS rating for conventional drain fields
The rating looks at the soil from 24 to 60 inches deep: permeability, depth to a seasonal water table or bedrock, flooding and slope. “Very limited” means at least one feature is unfavorable enough that a conventional field is hard to make work.
Show as a table
| Category | Shelby County | Tennessee |
|---|---|---|
| Not limited | 0.0% | 0.1% |
| Somewhat limited | 13.6% | 12.7% |
| Very limited | 84.0% | 81.9% |
| Not rated | 2.4% | 5.3% |
Rain, runoff and water table
Hydrologic soil group, flooding, seasonal water table
Hydrologic soil group
How fast rain soaks in when the soil is already wet. Group A soaks in fastest, D slowest.
Show as a table
| Category | Shelby County | Tennessee |
|---|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 1.9% | 9.9% |
| B: moderate infiltration | 27.3% | 39.3% |
| C: slow infiltration | 24.7% | 19.3% |
| D: very slow infiltration (clayey, shallow or wet) | 13.4% | 13.2% |
| A/D: D as is, A if drained | 0.0% | 0.0% |
| B/D: D as is, B if drained | 6.8% | 5.7% |
| C/D: D as is, C if drained | 15.0% | 6.4% |
| Not rated | 11.0% | 6.2% |
Flooding
Show as a table
| Category | Shelby County | Tennessee |
|---|---|---|
| No flooding | 57.4% | 80.3% |
| Rare or very rare | 0.9% | 1.4% |
| Occasional | 23.2% | 8.5% |
| Frequent or very frequent | 18.1% | 5.0% |
| Not reported | 0.4% | 4.8% |
Seasonal high water table
Show as a table
| Category | Shelby County | Tennessee |
|---|---|---|
| Within 18 inches at some time of year | 25.3% | 12.1% |
| 18 inches to 3.3 feet | 33.4% | 10.5% |
| Deeper than 3.3 feet or none reported | 40.9% | 73.0% |
| Not reported | 0.4% | 4.4% |
Topsoil pH and texture
First mineral layer of each soil
Typical topsoil pH is 5.3 (strongly acidic); 80% of rated land falls between 5.0 and 7.3. Median topsoil organic matter is 1.5%.
Show as a table
| Category | Shelby County | Tennessee |
|---|---|---|
| Strongly acidic (below 5.5) | 55.8% | 58.1% |
| Moderately to slightly acidic (5.5–6.4) | 19.2% | 26.3% |
| Near neutral (6.5–7.3) | 22.6% | 9.3% |
| Alkaline (7.4 and up) | 0.0% | 0.1% |
| Not reported | 2.4% | 6.2% |
Texture
Show as a table
| Category | Shelby County | Tennessee |
|---|---|---|
| Sandy | 0.5% | 0.7% |
| Loamy (loam, silt loam and similar) | 91.5% | 91.8% |
| Clayey (40%+ clay) | 5.6% | 1.3% |
| Organic (muck or peat) | 0.0% | 0.0% |
| Not reported (rock, urban land, etc.) | 2.4% | 6.2% |
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
- Shelby County, Tennessee (FIPS 47157): 489,057 acres of mapped land, 29,176 acres of open water excluded. State comparisons pool all mapped land in Tennessee.
- Method
- Shares are by mapped land area: each map unit’s acres in the county times each soil component’s percentage. Open water is excluded. Topsoil values use the first mineral horizon of each component. Full methodology.