Formerly a gas station, PlantWorks at 725 Main Street is a one acre community park conceptualized to serve two functions; it utilizes phytoremediation plantings to improve the quality of the existing soil and doubles as a public nursery, creating a free source of plant material for the Town.
Easy to maintain rows of small plants are installed and propagated as nursery stock for transplanting to other public projects. With a limited budget, the project achieves the Town’s goal of providing a beautification planting along this main gateway into downtown. However, the success of this project is in its dual purpose as a productive phyto and nursery landscape, resulting in an attractive display garden aesthetic.
Function One: A free source of plants for Public Agencies
The first park function conceptualized makes daily park maintenance one and the same with the nursery production process. Public agencies have very few funds to purchase plants for landscape projects, so PlantWorks serves as both a beautification gateway for the town, and generates nursery stock for other public projects. Rows of single types of low maintenance plant materials, well adapted toCape Cod’s sandy soils, were laid out across the site with walking and maintenance paths between the beds. Inspired by theCape Codvernacular, Plants chosen were all yellow or blue in color to provide visual bands of color and repetition for the high-speed traffic moving by. In addition, as many native, habitat enhancing species as possible were chosen with storm water filtration qualities a first priority. The landscape architect was soliciting the client to create a series of rain gardens in near-by public parking lots, so storm water filtration qualities were highly desirable in the plant selection process. The finished appearance is a botanical display garden, with all plants labeled with botanical and common name tags that also convey the benefits of low- maintenance gardening; it provides a demonstration garden of home landscape ideas. Since the projects completion in July 2007, almost every row of plants has been divided and harvested at least once, benefiting three other public projects which otherwise would never have been completed due to lack of public funds for landscape improvements.
Function Two: Clean the Site | Phytoremediation
Complimenting the nursery, Phytoremediation plantings were created in several areas of the site to passively remediate found hydrocarbons and lead where hotspots existed. While by EPA standards the site was ‘clean’, the landscape architect [LA] noticed in the soils reports that some background levels of lead and hydrocarbons still existed in several boring sites. The LA contacted experts in the field at Harvard University and learned that plants specifically suited to treat these contaminates could clean the site of its remaining background levels. Since the project had very little funding to hire other subconsultants, the landscape architect solicited a group of graduate students at Harvard to help research the best means of treating the contaminates. After working with the students during a semester-long independent study sponsored by the university’s department chair, the landscape architect devised a matrix of plants that would remediate each contaminate found onsite. Three types of phytoremedation plantings respond to conditions found in the soils. Type 1: Red Fesuce plantings treat the highest levels of lead found (The lead was still below EPA levels deemed safe, but higher than what would typically occur on theCape). Type 2: Sunflower seedlings remediate moderate levels of lead found. Type 3: Wildflower Meadow installation uses a combination of phytoremediation plants to both treat lead and hydrocarbons found in the upper levels of the soil.