County soil summary
Soil types in Charles County, Maryland
The most widespread soils are Beltsville, Grosstown and Marr; the most common drainage class is moderately well drained (35% of the land), and typical topsoil pH is 4.3.
- Well or moderately well drained
- 69% of land · state 70%
- Typical topsoil pH
- 4.3 extremely acidic · state 5.4
- Septic fields very limited
- 97% of land · state 85%
- Subject to flooding
- 14% of land, any frequency · state 10%
Most common soils in Charles County
Share of mapped land
A county is a patchwork of many soils. These 8 cover 69% of the mapped land; 32 named soil series are mapped here in all.
| Soil | Share of land | Drainage | Topsoil pH |
|---|---|---|---|
| Beltsville | 22.9% | Moderately well drained | 4.2 |
| Grosstown | 12.3% | Well drained | 4.1 |
| Marr | 8.7% | Well drained | 5.1 |
| Potobac | 8.0% | Poorly drained | 4.7 |
| Woodstown | 4.6% | Moderately well drained | 5.7 |
| Reybold | 4.5% | Well drained | 6.2 |
| Hoghole | 4.2% | Excessively drained | 3.6 |
| Lenni | 4.1% | Poorly drained | 4.5 |
What this means
What the soils in Charles County mean for gardens, lawns and septic systems
For your garden
Typical topsoil in Charles County is extremely acidic: pH 4.3 (most land between 4.1 and 5.0). 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 89% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (45% of the land).
69% of the land is moderately well to excessively drained, which suits most garden plants.
For your lawn and yard
On 65% 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 29% 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 97% of the land in Charles County very limited, 1% somewhat limited and 0% not limited (2% not rated, such as urban land, pits or water).
Statewide, 85% of the land is very limited, so Charles County is more restrictive than typical.
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 14% of the land (4% occasional, 10% 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 moderately well drained (35%). 69% of the land is moderately well drained or better, compared with 70% across Maryland.
Show as a table
| Category | Charles County | Maryland |
|---|---|---|
| Excessively drained | 4.2% | 1.3% |
| Somewhat excessively drained | 0.5% | 1.9% |
| Well drained | 29.5% | 48.1% |
| Moderately well drained | 34.5% | 18.2% |
| Somewhat poorly drained | 12.5% | 4.5% |
| Poorly drained | 14.6% | 12.9% |
| Very poorly drained | 1.7% | 6.3% |
| Not rated | 2.4% | 6.8% |
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 | Charles County | Maryland |
|---|---|---|
| Not limited | 0.0% | 0.5% |
| Somewhat limited | 1.0% | 7.6% |
| Very limited | 96.6% | 85.4% |
| Not rated | 2.4% | 6.5% |
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 | Charles County | Maryland |
|---|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 15.5% | 10.9% |
| B: moderate infiltration | 19.5% | 26.7% |
| C: slow infiltration | 36.1% | 25.7% |
| D: very slow infiltration (clayey, shallow or wet) | 9.6% | 11.6% |
| A/D: D as is, A if drained | 1.2% | 4.5% |
| B/D: D as is, B if drained | 13.3% | 5.3% |
| C/D: D as is, C if drained | 4.9% | 12.8% |
| Not rated | 0.0% | 2.5% |
Flooding
Show as a table
| Category | Charles County | Maryland |
|---|---|---|
| No flooding | 85.6% | 86.8% |
| Rare or very rare | 0.0% | 0.2% |
| Occasional | 3.9% | 2.6% |
| Frequent or very frequent | 10.2% | 7.5% |
| Not reported | 0.2% | 2.9% |
Seasonal high water table
Show as a table
| Category | Charles County | Maryland |
|---|---|---|
| Within 18 inches at some time of year | 28.8% | 25.1% |
| 18 inches to 3.3 feet | 35.1% | 18.9% |
| Deeper than 3.3 feet or none reported | 35.9% | 53.1% |
| Not reported | 0.2% | 2.8% |
Topsoil pH and texture
First mineral layer of each soil
Typical topsoil pH is 4.3 (extremely acidic); 80% of rated land falls between 4.1 and 5.0. Median topsoil organic matter is 4%.
Show as a table
| Category | Charles County | Maryland |
|---|---|---|
| Strongly acidic (below 5.5) | 93.8% | 50.9% |
| Moderately to slightly acidic (5.5–6.4) | 2.6% | 33.6% |
| Near neutral (6.5–7.3) | 1.2% | 7.0% |
| Alkaline (7.4 and up) | 0.0% | 1.1% |
| Not reported | 2.4% | 7.5% |
Texture
Show as a table
| Category | Charles County | Maryland |
|---|---|---|
| Sandy | 7.0% | 9.5% |
| Loamy (loam, silt loam and similar) | 89.0% | 78.4% |
| Clayey (40%+ clay) | 0.0% | 0.0% |
| Organic (muck or peat) | 1.5% | 5.8% |
| Not reported (rock, urban land, etc.) | 2.4% | 6.3% |
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
- Charles County, Maryland (FIPS 24017): 292,799 acres of mapped land, 18,228 acres of open water excluded. State comparisons pool all mapped land in Maryland.
- 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.