We assessed the capacity for nutrient removal of ornamental water garden plants being grown in treatment-production wetland biofilters. Plant biomass, nutrient uptake, tissue nutrient content, and production potential were compared for five popular ornamental water garden plant species: Typha latifolia L., Iris pseudacorus L., Phalaris arundinacea L. `Picta', Canna glauca L., and Colocasia esculenta (L.) Schott. Plants were grown in triplicate 0.3 m2 × 0.3 m, deep gravelbed mesocosms fed with 20N-20P-20K Peter's fertilizer (Scotts-Sierra Horticultural Products Co., Marysville, Ohio) reconstituted to 100 ppm N. After 120 days, mean species total biomass ranged from 1.4 to 5.6 kg·m -2, while producing 105 to 206 divisions per square meter. Growth for Canna and Colocasia was greatest, while Typha produced the most divisions. Mean tissue N and P concentrations ranged from 18 to 29 and 2.1 to 3.0 mg·g -1, respectively. Maximum plant accumulation of 144 g N/m 2 and 15.6 g P/m2 accounted for 70% of the N and 15% of the P supplied by fertilizer. Mean removal of total N and P ranged from 42% to 90% and 18% to 58%, respectively, and was positively correlated with plant biomass. Nutrient removal ability was ranked as Canna = Colocasia > Typha > Iris = Phalaris.