Re-Gardening Week 1 – Research On Plants

This week is week 1 of my Senior Project, and I start my project with research on the types of bioretention plants. The goal of this project is to redesign BISV gardens with bioretention plants so they are environmentally friendly while requiring low maintenance.

First, I looked into what are bioretention gardens, and how I should change the current garden to fit the bioretention plants’ function. By definition, bioretention gardens are “a shallow depression planted with deep-rooted, native plants selected to tolerate both drought and inundation conditions and designed to treat and filter stormwater pollutants.” Due to California’s weather, I shifted my research to focus more on the “drought” aspect rather than “inundation.” I then looked into the science behind bioretention gardens:

Bioretention gardens often locate in a dented field on the ground(lower elevation from roads). When rains, the rainwater will wash contaminants on the street and flows toward the garden due to gravity. If plants are not resistant to contaminants in the rainwater, they will shrink or die off, while the water flows through the soil and contaminate the groundwater. However, if the plants have filtration abilities, their roots will “grab on” to the contaminants and purify the water. Thus, the rainwater will not contaminate the groundwater as it drains.

Through internet research, I found multiple plant lists offering information such as the zoning information(which weather/location the plant thrives in), size of the plant, maintenance requirement, water demand, along with the chemicals the plant can purify from rainwater. However, each different plant list offers different information. This makes the process of connecting, comparing, and contrasting plants very difficult. To solve this problem, I decide to select plants through categorization of size and then research each plant individually.

Below are screenshots of two sample plant lists I looked into for the past week. One can see that although both of them provide information such as name, size, and water usage, information on plants’ growing conditions and retention functions is very limited, so I decided to focus on plants that occur most often for different lists and examine how suitable are they in adding on to the new design.

After a round of research, my goal for next week is to further look into potential plant candidates for planting. I will also begin measuring the size of the garden and start a scaled drawing for a diagram of the design.   

Works Cited: 

1. “Recommendations for Bioretention / Rain Garden.” Great Rivers Greenway, 29 June 2018, https://greatriversgreenway.org/design-guidelines/environmental/bioretention-rain-garden/.
2. “Design Criteria Manual for Stormwater and Landscaping.” VTA, https://www.vta.org/stormwater/design-criteria-manual-stormwater-and-landscaping.
3. Memorandum to: From: Subject: Director’s Recommendation: Executive Summary. https://sfport.com/sites/default/files/Item%207A%20USACE%20Feasibility%20Cost%20Sharing%20Agreement%20Amendment%2005.20.20%20%28S%29.pdf.