The invention is a phytoremediation test cell that mimics mature plant remediation properties. The test cell allows a test of the accuracy and efficiency of phytoremediation by placing the trees that are to be used for phytoremediation in a contained elongated cavity filled with the soil or root medium that is to be phytoremediated. The cell has a drain outlet at its bottom that water poured through the cell is in contact with the roots of the phytoremediating plant and then drains through the outlet such that it can be tested. The plants are 8-10 months old and arranged in the cell such that their roots are surrounded and in direct contact with the root medium.
