We conducted four trials to determine if we could alter root morphology of containerized Oregon white oak seedlings in order to potentially improve their performance in restoration plantings. Early pruning of the radicle produced a branched taproot, though with fewer branches than reported for other oak species. Pruning the taproot at 15 cm (6 in) promoted greater taproot branching than radicle pruning but did not increase formation of lateral roots. Nontransplanted seedlings grown in tall containers (2.83 L; 0.75 gal) responded to air-pruning with increased lateral root growth and minimal circling of roots. Inoculation with soil contain- ing ectomycorrhizal fungi substantially improved shootand root-growth response to fertilization.