Greenhouse studies were conducted to assess the impact of organic matter additions on plant uptake of DDT [2,2-bis(chlorophenyl)-1,1,1-trichloroethane] from weathered soil. Cucurbita pepo ssp. pepo cv. Howden pumpkins were grown in 100 g of DDT contaminated soil ([DDT] - 1100 ng/g) mixed with equal volumes of either clean soil, perlite, vermiculite, peat, potting soil, or granular activated carbon (GAC) to give total organic carbon contents of 2.4%, 2.5%, 2.6%, 11.5%, 12.2%, and 27.3%, respectively. As in other studies, root DDT concentrations were significantly lower in soils with high organic matter. Root bioaccumulation factors (BAF = [DDT]root/[DDT]soil) approximated this trend. Root concentrations correlated with organic matter concentrations and not with soil DDT concentrations. Conversely, shoot DDT concentrations, shoot BAFs and translocation factors (TLF = BAF(shoot)/BAF(root)) were not significantly different between treatment groups, except for plants grown in GAC/DDT soil. This suggests that amendments with a range of organic matter contents may be added to improve soil conditions at industrial sites without significant adverse effects on phytoextraction potential of C. pepo ssp. pepo.