State soil summary
Soil types in Delaware
The most widespread soil series in Delaware are Fallsington, Hammonton, Woodstown. Pick a county below, or enter a ZIP code for the county you live in.
- Well or moderately well drained
- 54% of mapped land
- Typical topsoil pH
- 6.0 moderately acidic · most land 5.0–6.3
- Septic fields very limited
- 88% <1% not limited
- Subject to flooding
- 11% of land, any frequency
Delaware counties
3 county reports, by population
| County | Most common soil | Well drained | Topsoil pH | Septic very limited |
|---|---|---|---|---|
| New Castle County | Reybold | 62% | 5.9 | 73% |
| Sussex County | Rosedale | 53% | 6.0 | 91% |
| Kent County | Fallsington | 51% | 6.0 | 95% |
What this means
What Delaware soils mean for gardens, lawns and septic systems
For gardens
Typical topsoil in Delaware is moderately acidic: pH 6.0 (most land between 5.0 and 6.3). Many vegetables grow well here, and some gardens benefit from a little lime. Test before adding any.
Loamy topsoil (loam, silt loam and similar) covers 52% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is loamy sand (25% of the land).
For lawns and yards
Most land is in hydrologic groups B and C, where rain soaks in at a moderate pace.
A seasonal high water table comes within 18 inches of the surface on 38% of the land, often in spring. Basements, sump pumps and lawns in low spots feel it first.
For septic systems
For conventional septic absorption fields, NRCS rates 88% of the land in Delaware very limited, 2% somewhat limited and <1% not limited (10% 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.
Flooding is mapped on 11% of the land (1% occasional, 10% frequent).
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Statewide mix
Share of all mapped land
Drainage
Show as a table
| Category | Share of land |
|---|---|
| Excessively drained | 2.7% |
| Somewhat excessively drained | 2.4% |
| Well drained | 31.5% |
| Moderately well drained | 17.7% |
| Somewhat poorly drained | 4.1% |
| Poorly drained | 16.9% |
| Very poorly drained | 14.9% |
| Not rated | 9.7% |
Septic absorption fields
Show as a table
| Category | Share of land |
|---|---|
| Not limited | 0.3% |
| Somewhat limited | 1.8% |
| Very limited | 88.2% |
| Not rated | 9.7% |
Topsoil pH
Show as a table
| Category | Share of land |
|---|---|
| Strongly acidic (below 5.5) | 25.8% |
| Moderately to slightly acidic (5.5–6.4) | 59.0% |
| Near neutral (6.5–7.3) | 3.4% |
| Alkaline (7.4 and up) | 1.9% |
| Not reported | 9.9% |
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
- Delaware: 1,122,167 acres of mapped land in 3 counties, pooled (not an average of county figures).
- 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.