Key soil properties - Pennsylvania counties

All soils are comprised of mineral particles in various sizes - sand, silt, clay - and organic matter, or decomposed plant and animal material. Parent sources of minerals and to a somewhat lesser extent the nature of the organic matter are responsible for soil reactivity, measured as pH.

The blend of physical elements directly relates to how well soils retain or shed water, and reactivity is an important factor in how efficiently plants can take up nutrients produced when water chemically reacts with minerals.

These values are among the first considered by gardeners in evaluating soils and considering landscape selections.

The National Resource Conservation Service (formerly the US Soil Service) of the USDA has mapped nearly all of the United States in terms of soil types and, through two free online services, landscapers can easily identify soils within a half acre of any location in Pennsylvania. How to find your soil. All data are organized by counties.

Definitions

These data discusses key soil properties for the top 12 inches of soils found in this county. The zone was selected because most home landscaping occurs within this depth. It is not necessarily the same as surface layer, which can vary widely with soil series and slopes. Source: National Resource Conservation Service, USDA

Sym - the map identifying code used by NRCS; learn how to find yours.

Name - the common series name of the soil sample, potentially supplemented with other descriptive phrases.

pH (1 to 1 Water) - Soil reaction is a logarithmic measure of acidity or alkalinity, with 7.0 being neutral. The lower the pH, the more acidic the soil, with pH 6.0 ten times more acidic than 7.0 and pH 5.0 ten times more acidic than 6.0.

Org - Organic matter; plant and animal residue at various stages of decomposition; expressed as a dry-weight percentage of material that is less than 2 millimeters in diameter.

Sand - Mineral soil particles between 0.05 millimeter and 2 millimeters in diameter; expressed as a dry-weight percentage of material less than 2 millimeters in diameter.

Silt - Mineral soil particles between 0.002 and 0.05 millimeter in diameter; expressed as a dry-weight percentage of material that is less than .05 millimeters in diameter.

Clay - Mineral soil particles less than 0.002 millimeter in diameter; expressed as a dry-weight percentage of the soil material that is less than .002 millimeters in diameter.

No data - Values shown as an asterisk (*) indicate that no values are available, often the case with urban land or features such as dumps and quarries.

Complexes

In some cases, more than one series is named in a soil map reference, i.e., Barbour-Craigsville. These result when a precise delineation of individual soils would be too small to efficiently map. A field inspection might yield clues as to which is present in a specific location, but if it's not clear, then it's generally safe to merge the features of the two series for landscape planning.

Pennsylvania counties and data

The Pennystone Project is a free public service resource for native plant landscapers in Pennsylvania.