There is something tremendously invigorating about moving through a colorful downtown landscape and coming upon a wall that is not just artistically decorated but is positively thriving. Vertical gardens—also known as “living walls”—are a perfect illustration of biophilic design, where the natural beauty of plants, flowers, and sometimes fruits and vegetables creates a kind of mural that would amaze even the most talented conventional painter. And plants can do that! Living walls can occur almost anywhere—inside or outside buildings—and they can take on almost any form that can be imagined. To breathe life into a wall that would otherwise be lifeless and to produce such a mural might be the most transcendently powerful act of creativity a visual artist can achieve.
The Impact of Vertical Gardens on Urban Living
One of the most powerful reasons vertical biophilic gardens speak to me is their ability to positively alter urban environments. In the world’s most condensed cities, where sprawling green spaces may be nonexistent, vertical gardens offer an ingenious solution to the scarcity of horizontal space. Instead of growing outward, we, in effect, grow upward—utilizing the naturally occurring vertical spaces in our urban environments to cultivate the biodiversity essential to not only maintain a healthy ecology but contribute to the psychological and physiological health of the human animals living in those environments.
Consider, for instance, the One Central Park building in Sydney, Australia. In the green oasis created by that vertical garden, the apparent harmony between nature and urban design should challenge the imagination of every architect across the globe.
The pros of these vertical green spaces go beyond mere appearance; their far-reaching effects touch on some of the most pressing issues of urban life. Air pollution is linked with a range of harmful health effects, and as much as we might like it to be otherwise, it seems we are not going to avoid living in polluted cities anytime soon. Therefore, finding ways to remove contaminants like nitrogen oxides and other pollutants from the air is crucial if we want to breathe more easily in the urban environment. Filtered air does seem a lot less harmful to inhale, and plants are essentially the low-tech, sustainable solution to accomplishing that overall aim. And their reach is only going to get higher if more and more vertical parks spring up in our polluted cities. Indeed, if Ilan weighs more than a pound, he might not make the cover of the next edition of Life. A more efficient way to live and to survive is for trees to thrive in the air of the city instead.
Practical Considerations for Designing Vertical Gardens
When I am asked about vertical gardens, the most frequent question concerns their maintenance. It’s sort of the $64,000 question: Wall plants sound great in theory, but what are the actual practicalities? Do they warrant the “living wall” label? To make the kind of vertical garden that has any hope of being successful, you need to give some thought to the plant material you are using. Not every plant works vertically or will survive in the specific microclimate of your chosen wall. Let’s work with some vertical-practice examples. To my knowledge, I’m the only person who has done a vertical succulent wall. When I designed mine at home, I used a mix of two plants: a Crassula and a relatively rare jade (which you’re not likely to find in garden centers—robotic assistants, please take note). In both cases, I was advised to be comfortable with their not being perfectly healthy.
One particular project comes to mind when I think about vertical gardens. It was for a corporate office in New York City; the space was indoors and had only moderate natural light. And yet we knew, going in, that the main challenge would be the building’s HVAC system. The flow of air was inconsistent and, to be blunt, the executive offices were in the direct path of an occasional blast of really cold air. Our main job was to select plants that wouldn’t be stressed by these conditions and that would thrive in an irregular climate. We went with pothos and philodendrons, which are super tough. I think of those two plants as being the “work-horse” plants of the indoor ecosystem. They can take a good amount of neglect, serve two main purposes in a living wall, and also fit the main wellness goals of an indoor vertical garden. Pothos purifies air. Philodendrons do too. And the air in that particular office was going to be so much cleaner as a result of our installation that it was really, in essence, a living wall dedicated to climate change work.
Addressing irrigation and pest control problems is just the beginning. The larger task falls on plant health, which has a much longer arc of responsibility and is more challenging to get right. One good story to tell about plant health involves a hotel lobby vertical garden for which I was a consultant. After six months, the plants became sick, showing signs of distress. When I investigated, I discovered that mealybugs had taken up residence among the plants.
The Mealybug problem forced into focus the importance of good ol’ human routine care and monitoring—my bad for not having a pair of sharp eyes looking at that plant assembly every couple of days. The solution was to introduce ladybugs as a natural predator to the mealybug. Despite being a bad place for plants, the Mealybug scenario was a real-world example of a plant health issue that—because we opted not to use harsh chemicals—had a favorable outcome.
The vertical garden can be potent in delivering satisfaction in space-making sometimes because it can be dramatic and surprise us with effects of shape, growth, and color. One of the most gratifying projects I have ever worked on involved taking a small, dreary courtyard of a very urban home and giving it identity and charm—and, with that, an illusion of space. The vertical garden in what I call “the birdcage” drew both the eye and the conjecture of anyone seeing the house. What I especially liked was how the space became a sanctuary for the birds and insects that had previously avoided this concrete dead zone. That is the space-making magic of biophilic vertical gardens, not just for us but for our living space mates.
The Future of Urban Design Is Vertical Gardens
I truly believe that biophilic vertical gardens are going to be an important part of the future urban design landscape. With the current trajectory of urban density, the types of spaces that we conventionally think of when we think of “nature” (like parks) are simply not going to be feasible in many parts of our cities. Vertical gardens, on the other hand, allow us to push that much closer to “greening” our built environments—an essential part, in my view, of any aspiring future city.
An outstanding instance of this proactive mode of thinking is Singapore’s current endeavor to be a “City in a Garden.” The city-state has taken the vertical garden to its heart and integrated this innovative living wall system into its world-famous skyscrapers, residential complexes, and public spaces. Strolling through Singapore, it is impossible not to feel that this city is different from other ambitious, cut-and-dry international business centers. Indeed, it is the only one of its kind. Singapore blends the vertical garden into its renowned profile, giving this cutting-edge world city a softness and a green pulse.
When I think about vertical gardens, I see them as something more than a component of “biophilic design,” a term that describes the natural elements, however small or large, that ostensibly bring the outside in when it comes to building interiors. Vertical gardens, in my view, provide a keystone framework for how we might reimagine architecture as nature and nature as architecture. They challenge the longstanding tendency to (figuratively, if not literally) wall off nature and create an environment that is perceived as separate—a “constructed environment” in which we humans can “exist” while leaving nature (and biodiversity) somewhere “out there.”
I have witnessed the bond between greenery and well-being in community projects where vertical gardens have been established in disadvantaged areas. Even in places where access to nature is constrained, the very sight of plants can have a marked effect. I remember accompanying the kids from the neighborhood to the top of an apartment building on a hot day, and the very first breath we took as we climbed the stairs to the rooftop spoiled the kids. It was the kind of breath that felt good on the lungs—deep, cool, and fragrant.
While we continue to wrestle with the problems presented by climate change, I’m convinced that vertical gardens are part of the answer. They mitigate the urban heat island effect, and by their vertical nature, they help insulate buildings, even as they offer much-needed space for biodiversity in cities where parks and other green spaces are at a premium. More than any of that, however, they make me hopeful. Hopeful that our cities can be green and vibrant. Hopeful that we can design a built environment that supports life in all its forms.
More than simply a design trend, biophilic vertical gardens offer an enticing glimpse into what sustainable, human-centered urban living might look like. And more than wanting to be a mere ally of vertical gardens, I embrace their potential to reimagine the built environment and reshape the future, one Eden at a time.
