Digging the Future of Vertical Gardens

By Denise Eichmann

Many businesses today are looking to green walls as a way of adding natural beauty while dramatically improving energy efficiency by moderating indoor air temperatures and humidity levels. A green wall, which is also referred to as a living wall or vertical garden, is a wall that is free standing or part of a building that is partially or completely covered with a vegetation facade. Inspired landscapers dig their shovels into their souls and plant their own nature into their work. Green walls provide an inspired palette for landscape architects to harness and cultivate the joyful power of nature to best serve their clients.

As living walls are becoming “de rigueur” as the environmentally forward plantings that every green-conscious business desires to visually showcase its green initiatives, shoddy systems with poor long-term performance are quickly flooding the market. Designing, building and installing beautiful yet functional and environmentally beneficial green walls takes experience and practice.

Living plants require water, nutrients and light to survive. High-quality commercial vertical gardens come complete with their own “life support” system, which is comprised of a supporting structure to hold the plants vertically, a growth medium to ensure plant longevity, an irrigation/fertilization system to deliver the correct amount of water and nutrients, and a drainage system to properly dispose of or re-circulate the spent water. Proper selection and design of a system for a particular locale necessitates plumbing and electrical considerations. Understanding the lighting needs required for the selected plants is also crucial for sustainability.

There may be countless reasons why vertical gardens are an important addition to any commercial property. The primary benefits of living walls are as follows:

Green walls roll out welcome wagon — You can’t help but be awed by the beauty of a living wall. Whether a green wall is showcased in an interior setting such as in a hospital, hotel or commercial lobby, or in full glory on the outside façade of a building, they make environments look more attractive and welcoming. Syed Hasan, general manager for Embassy Suites Chicago Downtown Lakefront, who unveiled Chicago’s largest indoor green wall in his hotel’s sky lobby in June 2011, believes that the new green wall rolls out a green welcome wagon to all guests and visitors. “Not only is our green wall beautiful to behold, but it actively improves the lifestyle of people in urban environments, as the average person spends a majority of their time indoors,” said Hasan. “Our green wall also assists in reducing noise levels, as plants absorb sound and improve energy efficiency by moderating indoor temperatures and humidity levels.”
Breath of fresh air — Vertical gardens provide a net positive impact to the environment over their life span. Foliage plants of indoor vertical gardens significantly improve indoor air quality by moderating temperature and humidity levels, and filtering the air to remove harmful volatile organic compounds (VOCs). VOCs are “chemicals” that have significant vapor pressures that can be dangerous to human health and have adverse effects on the environment. The EPA has found concentrations of VOCs in indoor air that is commonly two to five times greater than what is found in outdoor air. Sources of anthropogenic (manmade) VOCs include new furnishings, wall and floor coverings, and office equipment. In the span of a year, a 50-square-foot vertical garden can consume as much CO2 as a 14-foot-high tree with as much as one pound of dust removed from the air per square foot.
Sign post value of living wall — Living walls can provide a living barrier that gently guides people to where you want them to go. In many buildings there is a need to channel pedestrian traffic toward landmarks including check-in desks, escalators and common passageways. This is particularly important in premises with large, open areas such as those found in airports, hospitals, universities and other large commercial spaces. Living walls provide natural divides and reference points that make any space come alive with vitality.
There are no ugly buildings, only lazy ones — Many buildings have features that are best kept covered, such as harsh structural elements, service areas and storage facilities. Vertical gardens — with their wide range of size, shape, habit and leaf form — can provide an elegant solution that is both attractive and functional. If properly designed and implemented, a green wall may positively affect securing certain LEED credits.
Striking a pose — Interior space planning is a fashion-driven business, and nothing “strikes a pose” more handsomely than an artful living wall. Interior living walls bring nature indoors, which is especially important in urban areas where the average person spends more time inside commercial or residential buildings than outside with nature. People are naturally attracted to plants and gravitate toward living walls where the sensory experience is captivating. Where else, other than the tropical plant houses of botanical gardens, will you see the variety of exotic and unusual plant species that can be found in some vertical gardens?

 The East Conservatory Plaza at Longwood Gardens, Kennett Square, Pa., features a terraced lawn, lush new plantings and the largest indoor green wall in North America. This colossal vertical garden features a panel wall system across a green wall surface area of 3,590 square feet, which includes more than 25 species of plants. “The East Conservatory Plaza embraces innovative landscape design, which captures the very essence of Longwood Gardens,” said Longwood Gardens Director Paul Redman. “The size and beauty of the green wall amazes and delights our guests as well as advances our continuing commitment to sound environmental practices.”

If you have the green-light to move forward on a living wall, keep in mind the following factors which are crucial to the garden’s longevity and success:

Location, location, location — The location of a living wall is significant; not only from a visual standpoint, but from a mechanical point of view. Is the desired location accessible to plumbing and electrical? What is the infrastructure of the supporting wall — is the green wall framing attaching to concrete, metal or marble? With the right infrastructure in place, nearly any location can be accommodated but the budget may be higher for a green wall location far from water lines and with no natural light.
Survivability of plants requires appropriate lighting — Most interior living walls require supplemental lighting. Establishing healthy lighting for plants entails knowing the light requirements of specific plant species, performing light studies, and collaborating with the electrician to specify fixtures to meet those requirements. Metal halide light fixtures and lamps provide the closest color temperature to natural sunlight and assist to promote photosynthesis, which is critical for plant survival. Adding photo luminescent sensors to the green wall is a smart decision, as it can reduce the electric consumption.
Plant selection is key — Your selection of featured green wall plants should be based upon microclimate conditions, plant growth habits, and the availability of light. An exterior north-facing wall requires an entirely different plant palette than a south- or west-facing wall. For example, featured plants on exterior walls in the arid southwest climate differ from what can be used in the cold Midwest. Plants for interior walls are chosen to reflect low, medium and high light scenarios. Interior tropical plants require a minimum of 10 to 12 hours of at least 150 foot candles of light per day to flourish. In a typical commercial hotel environment, there are on average about 30 to 40 foot candles of light vs. 5,000 to 10,000 foot candles of light that can be found outside on a bright sunny day. Interior Plants that thrive in low light (75 to 150 foot candles) include the Scindapsus and Philodendron genus such as the Silver Satin Pothos, Neon Pothos, Golden Pothos, Jade Pothos, and Heart-leaf Philodendron. Medium light thriving plants (100-250 foot candles) include the Dallas Fern, Cretan Brake Fern, Rabbit Foot Fern, Begonia and Peperomia species. For environments with maximum light (150 to 250 foot candles), plants such as the Alocasia Amazonica, Hawaiian Schefflera, Hedera Ivy, Purple Waffle Plants and Creeping Fig are ideal.

The average person today spends about 90 percent of their time indoors, with about half of the world’s population living in cities. Green walls improve a building’s air quality, and enhance the emotional and physical well being of the people who come into contact with them. Green walls act as acoustic barriers, which can counter the noise pollution that plagues urban dwellers. Green walls harmonize buildings with nature, and provide a living canvas for green wall professions to add the beauty of nature to any manmade structure.

Denise Eichmann is senior project manager and design expert for Ambius, a leader of enriching the workplace. She is internationally recognized for the design and construction of uniquely challenging, one-of-a-kind sustainable landscape projects. Eichmann is a Certified Landscape Professional (CLP) whose newest area of expertise focuses on the design, construction and installation of vertical gardens and living walls. She can be reached via e-mail at denise.eichmann@ambius.com

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