Plant roots influence the soil in which they grow in a variety of ways, making the soil more conducive for microbial growth and activity, as well as cometabolic reactions. Studies examining the fate of pesticides in plant-soil systems have revealed a marked decrease in persistence of these compounds. Additionally, similar observations have recently been made for oil residues, polycyclic aromatic hydrocarbons, trichloroethylene, and surfactants. These previous studies suggest that the root zone could potentially be managed to effect bioremediation of surface soils containing hazardous organic compounds through enhanced biochemical transformation of these organic constituents at waste sites by indigenous rhizosphere microorganisms. In order to further test this hypothesis, a study was initiated using soil and vegetation from an existing pesticide-contaminated site in Iowa. Initial characterization of this site revealed several herbicide-tolerant plant species including Kochia sp., knotweed (Polygonum sp.), and crabgrass (Digitaria sp.). Experiments testing the influence of these tolerant varieties on microbial degradation of a mixture of herbicides are reported. By facilitating microbial degradation of pesticide wastes, vegetation could provide a cost-effective and ecological approach to restoration of contaminated surface soils in situ.