State soil summary
Soil types in New Hampshire
The most widespread soil series in New Hampshire are Tunbridge, Marlow, Monadnock. Pick a county below, or enter a ZIP code for the county you live in.
- Well or moderately well drained
- 69% of mapped land
- Typical topsoil pH
- 4.8 very strongly acidic · most land 4.2–5.5
- Septic fields very limited
- 79% <1% not limited
- Subject to flooding
- 2% of land, any frequency
New Hampshire counties
4 county reports, by population
| County | Most common soil | Well drained | Topsoil pH | Septic very limited |
|---|---|---|---|---|
| Hillsborough County | Canton | 83% | 4.8 | 91% |
| Rockingham County | Canton | 69% | 4.8 | 93% |
| Merrimack County | Tunbridge | 79% | 4.8 | 95% |
| Strafford County | Gloucester | 72% | 5.1 | 89% |
What this means
What New Hampshire soils mean for gardens, lawns and septic systems
For gardens
Typical topsoil in New Hampshire is very strongly acidic: pH 4.8 (most land between 4.2 and 5.5). 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 65% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is fine sandy loam (45% of the land).
69% of the land is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 54% 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.
For septic systems
For conventional septic absorption fields, NRCS rates 79% of the land in New Hampshire very limited, 5% somewhat limited and <1% 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.
Statewide mix
Share of all mapped land
Drainage
Show as a table
| Category | Share of land |
|---|---|
| Excessively drained | 5.2% |
| Somewhat excessively drained | 11.2% |
| Well drained | 37.5% |
| Moderately well drained | 15.0% |
| Somewhat poorly drained | 0.3% |
| Poorly drained | 8.7% |
| Very poorly drained | 5.0% |
| Not rated | 17.1% |
Septic absorption fields
Show as a table
| Category | Share of land |
|---|---|
| Not limited | 0.2% |
| Somewhat limited | 5.3% |
| Very limited | 79.1% |
| Not rated | 15.4% |
Topsoil pH
Show as a table
| Category | Share of land |
|---|---|
| Strongly acidic (below 5.5) | 70.4% |
| Moderately to slightly acidic (5.5–6.4) | 8.5% |
| Near neutral (6.5–7.3) | 0.2% |
| Alkaline (7.4 and up) | 0.1% |
| Not reported | 20.8% |
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
- New Hampshire: 5,770,547 acres of mapped land in 10 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.