Plants and their associated organisms can be used for environmental cleanup in the technology entitled phytoremediation. Amongst various number of trees, poplars and willows present most oftenly used tree species in the northern hemisphere. Up to date research in Serbia mostly involved investigation of potential of different poplar and willow clones for heavy metals, nutrients and hydrocarbons phytoremediation. This paper presents investigation of the potential for phytoremediation of persistent herbicides Goal and Racer through testing of effects of these herbicide on physiological and biochemical parameters of mentioned species.