Deep‐rooted trees planted as a buffer zone can intercept runoff and eroded sediments, thus reducing non‐point‐source pollution due to agricultural chemicals. In this study, Populus sp. were grown in bioreactors with an agricultural soil (silt‐loam) and in a silica‐sand media; both were spiked with ¹⁴C uniformly ring‐labeled atrazine. The plants took up over 11% of the ¹⁴C labeled atrazine applied to the silt‐loam soil and over 91% of that applied to the silica sand media, with the majority of the ¹⁴C accumulating as nonphytotoxic metabolites in the leaves. Research suggests that, in addition to nutrient uptake, poplar tree buffer strips may be effective in removing atrazine from agricultural percolation and runoff water.