Dr. Nina Bussuk and her team at the Cornell Urban Horticulture Institute work to find and study versatile, multifunctional plants for cities.
Talk with Dr. Nina Bassuk long enough and you realize she’s on a mission to help horticulturists and engineers rethink plants in cities, especially for stormwater design and planting. As the head of Cornell University’s Urban Horticulture Institute, Nina has made it her business to create functional landscapes with multifunctional plants.
One of the most common stormwater management practices is bioswales/rain gardens. Nina told the Cultivate’15 audience that these stormwater features are mostly spec’d with wetland plant species, many of them requiring low pH. The problem is that most of the time it’s not raining, she added. And, in places like upstate New York, soils are not acidic.
Nina and her team are looking for plants that tolerate a wider range of growing conditions and still provide landscape functionality. She says that rather than thinking only of native wetland species, we need to expand the palette. We need to be thinking of what she terms “adapted plants”– Plants that function well within a wide range of moisture conditions and across a range of soil pH. Adapted plants may or may not be indigenous to the area.
In terms of landscape functionality, bioswales and/or rain gardens serve to primarily infiltrate and store stormwater. Vegetated stormwater features like bioswales along roads are more and more common. For stormwater features like these, salt tolerance in the plant selection is paramount, especially in northern climates. But so is beauty. When the stormwater feature is along high visibility transit corridors and institutional or municipal gateways, it needs to reflect the pride and character of the location.
Nina’s work with woody plants and small trees for stormwater is also about maintenance. Most shrubs and small trees don’t require regular cutting back as herbaceous plants might. Planted correctly, they also achieve ground cover within two to three years, which limits the amount of weeding that’s required too.
Her team has also published Woody Shrubs for Stormwater Retention Practices, 56 pages of information and tips on plants and how to use them in filter strips, swales and rain gardens. Profiles for 35 woody shrubs are included, including six plants that were tested for three months for flood and drought tolerance by Ethan Dropkin a former graduate student.
NewTerrain newsletter September 4, 2015.