Green Infrastructure: Vegetated Walls is part of a series of posts that explore some of the Best Management Practices (BMPs) of Green Infrastructure and Low-Impact Development (LID) for both urban and rural applications. The IRWP is currently working with our local cities, counties and organizations to implement green infrastructure and LID elements within the Illinois River Watershed. Watch for these demonstration projects in public spaces to see first-hand non-point source management in action!
Environmentally conscious designers, architects, residential homeowners, schools, and more groups are finding another type of canvas for growing plants – vertically! Vegetated walls, also referred to as green walls or vertical gardens, have endless possibilities with the many types of structures and growing containment systems available. From functional to artistic, green walls are finding their way into many communities, and for a good reason.
We know that plants can help purify the air. What if you multiplied that benefit by adding hundreds, or even thousands of square feet of vertical green space? Studies show that vegetated walls, both indoors and outdoors have a multitude of benefits – not just air purification.
Indoors, a vegetated wall can be aesthetically pleasing, and people surrounded by plants are happier, healthier, more content, creative, productive and relaxed (Association for Psychological Science). Indoor systems can have cost benefits too, by conserving energy and regulating air temperatures. Outdoors, a green wall can help mitigate the urban heat island effect by cooling the air, slowing air movement and detoxifying air-borne pathogens. They can also reduce noise, reduce erosion, recreate habitat for butterflies, birds and insects, and can serve as excellent outdoor classrooms. They work to provide on-site water treatment and can be scaled in any urban setting.
Vegetated retaining wall system. Source: Houzz.com
There is what seems like a variety of systems, but really there are two main types. Wall systems where climbing plants or cascading groundcovers are trained to cover specially designed supporting structures, like a trellis or cable. Plant materials can be rooted at the base of the structures, in intermediate planters, or on rooftops. These can be attached to existing walls or built as freestanding structures. The other is composed of modular materials such as pre-vegetated panels, fabric systems attached to the wall, or vertical block systems – which can double as retaining walls. This system supports a great diversity of plant species, including a mixture of groundcovers, ferns, perennial flowers, and edible plants because it uses a soil blend and irrigation within the system.
Eco Modern Flats, a multi-dwelling unit in Fayetteville, AR, uses the green wall to reduce ambient temperatures on the south side of the building and doubles as screen for outdoor spaces. They used Hops, a vine that is well-suited for our zone.
For outdoor vegetated walls, it does matter the orientation of the wall and sun/shade conditions. Different plants require different conditions, just as the horizontal landscape calls for. Woolleypocket.com has an excellent plant list to refer to and provides some great resources on school vegetated walls. In Spring 2015, the Partnership will be installing our new vegetated wall, as part of our Low Impact Development (LID) installation at out Watershed Learning Center in downtown Cave Springs, Ark. Stay tuned for updates on our progress on our website and Facebook!
The Illinois River Watershed Partnership works to improve and restore the Illinois River Watershed through public education, water quality monitoring, and conservation/restoration projects. Check out our website for current events that continue to educate stakeholders of the Illinois River Watershed about Green Infrastructure and Low Impact Development, as well as events that offer volunteer opportunities to make a positive difference! [www.irwp.org]