Many Berkshire soils lack the eluvial (E) horizon characteristic of podzols because they have a history of being cleared for cultivation.
The deep glacial till which provides the foundation of the Berkshire series contains material derived from mica schist with fragments of gneiss, granite and phyllite also present in some areas.
These rocks are not high in mineral nutrients but provide enough fine-grained material to produce a loamy soil.
Many Berkshire soils, however, are too rough and stony for easy cultivation and have been allowed to revert to forest.
Several species of maple, birch and pine are prominent among the trees, along with beech, spruce, fir, ash and basswood.