Wetland value is threatened by invasive plant species such as Reed Canarygrass (Phalaris arundinacea). Hence the research objectives of this project were to determine if reed canarygrass abundance has an effect on plant species diversity and assess the effectiveness of novel treatments on reed canarygrass control in a constructed wetland. Four treatments (mowing, herbicide, mowing plus herbicide, and a control) followed by broadcast seeding were applied to regulate growth of reed canarygrass. Principal components analysis, biodiversity measures, and ANOVA were used to identify community composition, quantify biodiversity values and identify treatment differences respectively. Results indicated differences in species composition between east and west blocks of the study site, reed canarygrass abundance appears to keep plant species diversity low, indigenous species were rare, and reed canarygrass was resistant to treatments.The results of this study are not surprising considering there is little evidence that treatments for reed canarygrass control are effective.