Green infrastructure grows up

Green infrastructure is a design strategy based on improving water quality and adding ecological functionality to new and existing development through the use of plant material. Communities around the world are conserving, restoring and enhancing natural areas by incorporating trees, rain gardens and vegetated roofs that mimic natural systems and achieve benefits including improved public health, economic development and reduced flood risk.

This technique relies on the use of soil and plants to manage storm water and create low-maintenance, healthy ecological systems. These designs can be used to reduce the need for expensive gray infrastructure, such as storm water drains, pipes, storage facilities and treatment systems. Considered a “triple bottom line effect,” green infrastructure saves municipalities and tax payers’ money, while improving the environment and adding to social appeal. Consider the carbon dioxide that is absorbed improving air quality, the increased property values as a result of the plantings and all of the new local green jobs installing, maintaining and growing the plants for these public spaces. Additionally, these planting systems create habitat and food for wildlife while protecting water quality by controlling soil erosion.

Designed to capture storm water, green infrastructure improves water quality by filtering polluted runoff before it reaches waterways. Plants and soils soak up, store, and use the rainwater. These designs help recharge groundwater systems and increase flows to streams, rivers, lakes and reservoirs. Added values include the minimal required maintenance and low irrigation needs once a site is established.

Big business

There is great diversity in the use and function of green infrastructure. Rain gardens, green roofs and walls, bridges, greenways, urban canopies and green parking lots are just a few examples of high impact designs meant to utilize natural resources and create quality environments.

“Everyone should agree upon an expanded definition of what green infrastructure means. We’re well beyond the world of rudimentary detention basins and bioswales and sedum green roofs,” says Patrick Cullina, principle of Patrick Cullina Horticultural Design + Consulting in New York City.

Photos courtesy of Brienne Gluvna Arthur

“A vastly more diverse realm of landscape systems are integral components in large, sophisticated and influential municipal projects.”

Examples of green infrastructure developments are being constructed across the U.S., and Cullina has lent his design acumen and horticultural expertise on many.

“The High Line is a bridge, as is Bethlehem Steel’s Hoover Mason Trestle. Hudson Yards and Manhattan West are platforms over active rail lines; Boston’s Rose F. Kennedy Greenway is the roof of a vehicular tunnel and nearby Pier 4 project is just that,” Cullina explains.

The nursery’s role

Many nurseries are growing plants appropriate for green infrastructure projects. Growers should find out what projects are being planned regionally, learn more about the environment those projects present and identify the plants in production that fit those conditions.

“As the GI [green infrastructure] market builds, there will be demand for a broader palette of plants. If you can work appropriate plants into your new production plans, you’ll be ready for it,” says Shannon Currey, marketing director at Hoffman Nursery in Rougemont, N.C. “We’ve been reviewing our offerings and expanding to include more native sedges, for example, because they work really well for many GI projects. Also, we’re adding more cultivars, especially those of native species, to have a wider variety for designers to choose from. Until the market is more mature, it may be difficult to gauge appropriate inventory. That’s where tapping into upcoming projects can help a lot.”

Nursery sales and marketing staff can begin to break down the barriers by communicating with designers working on GI projects.

“Nurseries need to do their part in responding to the potential market but they can’t do it without the designers who can help to build that market with a more considered and nuanced approach to design,” says Cullina.

Currey also suggests that growers connect with the landscape architecture and engineering firms, municipalities, regional authorities and non-profits that are planning green infrastructure projects.

“We’ve been using connections to find out what’s happening around us. In some cases, we’ve been able to be a part of the planning process. That allows us to know when plants are needed and have them ready and to custom grow plants that we might not otherwise include in regular production. That’s a way to bridge that gap between supply and demand until the market becomes more stable,” Currey says.

Follow up with contractors to get feedback on how plants are performing.

“Direct experience from existing projects helps us get a read on whether a plant should be marketed for GI,” she says.

Green infrastructure awareness and education are essential for moving the nursery industry forward in this market. Embrace the opportunities ecological design offers and promote horticulture as a solution for community health and wellness for generations to come.

Top photo: The Brooklyn Bridge Park is an 85-acre sustainable waterfront park that incorporates a number of green infrastructure projects. Stretching 1.3 miles along the East River, this multi-use green space is made up of seven interconnected ecosystems that enhance the human experience and provide habitat for an abundance of wildlife.

Brie Arthur is a plant propagator, landscape designer and green-industry communicator based in Raleigh, N.C.

Click here to read the full article, including a list of recommended trees and shrubs for GI projects on the East Coast.