<p>Landfill leachate contains a wide range of pollutants in varying concentrations, resulting from the degradation of urban solid waste. In contrast to conventional treatments, constructed wetlands offer a more environmentally friendly alternative for treating landfill leachate. This work aimed to evaluate the exposure effects of a closed landfill leachate located at the facility of an urban solid waste treatment plant on the germination and growth of <i>Canna glauca</i> at laboratory-scale and microcosm-scale wetlands, respectively. In the experiments, <i>C. glauca</i> seeds and seedlings were exposed to leachate concentrations of 0%, 10%, 25%, 50%, 75%, and 100%. During the experiments, seed germination and the height of the shoots were assessed. At the end of the germination experiment, the germinated seeds were counted, and calculations were made to obtain different toxicity indices. Although seed germination and shoot growth decreased in treatments of 75% and 100%, it was concluded that the threshold value for leachate toxicity is a concentration of 50%. The obtained results suggest that the studied landfill leachate is a moderately toxic wastewater. Since <i>C. glauca</i> demonstrated a good adaptive response and tolerance, it is a suitable species to be used in constructed wetlands for landfill leachate treatment.</p>