Evaluating Vegetation and Growing Media for High-Performing Bioretention

Over the last decade, the use of bioretention to solve complex stormwater problems has increased throughout the world and in many large jurisdictions in the United States. As these facilities have been built and maintained it has become apparent that plant health is one of the major drivers of increasing life-cycle costs, and that fast-draining inorganic media and improper plant selection are the key culprits to poor plant establishment and health. This presentation will focus on the selection of vegetation and different growing media for high-performing bioretention facilities. It will include data from monitoring of plant health and media functionality, the impact of poor plant health on maintenance programs, and considerations on balancing the aesthetic goals of projects with the functional aspects of bioretention to detain, infiltrate, and release stormwater. The presentation will conclude with actionable steps for designers and municipal staff to consider when selecting components of a bioretention system, particularly plants and growing media, and how they can fit together to accomplish projects goals.