We examined how buffering capacity affected natural earthworm communities by comparing well-buffered soils in Madison County in central New York and poorly buffered soils in the western Adirondacks. We also investigated how liming and interspecific competition influenced growth and survival of 2 exotic taxa (Eisenia foetida and Amynthas agrestis) in Adirondack and central New York soils using laboratory microcosms. Earthworms were more abundant and diverse in central New York soils than in western Adirondack soils. Interspecific competition had no effect on growth or survival of either species in microcosms. Survival of A. agrestis was low in Adirondack soils without lime, but liming increased survival to that of central New York soils. Growth rates of E. foetida were lowest in Adirondack soils without lime, but highest in Adirondack soils with lime. Our results suggest that high soil acidity may be preventing exotic earthworms from successfully invading the western Adirondacks.