The Living Wall

A Breath of Fresh Air

by Lindsey Westbrook

To see all of SFMOMA’s galleries now involves a multiple-mile trek. That’s the most important raison d’ȇtre for the Living Wall, a green, leafy respite from the succession of white-box spaces. Visitors wishing to momentarily go outside and rest their eyes—on something alive, that moves in the wind and can even be touched—will be rewarded there. They will occasionally find birds, butterflies, and bees, and for repeat visitors a play of textures and colors that changes with the seasons.

At thirty feet high and 4,400 square feet in expanse, it’s currently the largest living wall in the United States. As Deputy Director Ruth Berson observes, “The Living Wall provides a wonderful backdrop to the sculptures installed on the third-floor terrace. And since it can be glimpsed from floors one through six of the new addition, the lush greenery is an orienting feature, not unlike the Atrium in the older part of the museum—a way to know exactly where you are in the expanded building.” It’s also a sculpture in its own right, but one carefully designed so as not to overtly compete with the works in the galleries for which it serves as a backdrop.

Lara Kaufman of Snøhetta shares the architectural backstory of the Living Wall: “We were busy with section studies, seeing how the new atrium might connect to the Botta atrium. When we landed on a plan to pull the mass of the building somewhat away from neighboring buildings, a terrace was created on level three—one that you could see from the Botta entry. It was an opportunity to do something amazing that would invite people to find their way from both the new and old entrances to a common starting point for the museum experience. The new lobby is lit with natural daylight and has views up to the Living Wall.”

In all of their projects, Snøhetta strives to incorporate landscape elements. “But SFMOMA is in a tight urban condition, without lots of opportunities for horizontal planted areas,” Kaufman continues, “so it was a big ‘aha’ moment: wouldn’t it be great to have a vertical garden, one that you could see from multiple floors!”

The architects contacted the go-to person for such gardens in the San Francisco Bay Area, David Brenner of Habitat Horticulture. Brenner’s résumé includes the 90-foot-tall garden scaling the outside of the Jasper building at Harrison and First Streets, interior walls at Autodesk and Trulia, and the twelve-by-eighteen-foot living stage at the California Academy of Sciences.

Brenner’s formal education is in horticulture, landscape design, and—importantly—psychology. He understands both scientifically and viscerally what a living wall brings to an urban space. “The benefits are both mental and physical,” he says. “Many studies prove the stress-relieving, restorative effects. When you take a break from whatever you’re doing, at work or otherwise, and look at some greenery—specifically shades of green, it’s been found—you return to what you were doing more efficiently. It lowers your heart rate, makes you feel connected to nature.”

SFMOMA’s verdant wall is mostly monochromatic, with just a few pops of color, its planted areas fading together and into one another. “Other installations I’ve done have distinguished swaths, more painterly strokes,” says Brenner, “whereas this one is inspired by the amorphous way lichen grows on rocks.”

The wall has four distinct microclimates based on year-round light exposure, and the plantings in each were curated according to what would thrive there. Many of the native species can be found on the forest floors of Mount Tamalpais, Muir Woods, and the East Bay Regional Parks, and their use in the wall is intended to elicit memories among locals, whether conscious or unconscious, of seeing them on hikes. These are known as “redwood understory,” and “mixed evergreen forest” types. Also in California there are particular species that grow in canyons, and their presence lends an additional nature reference to the urban canyon that the wall occupies.

Living walls can be difficult to sustain in drought-prone California, but a number of clever features engineered by Habitat Horticulture’s partner, Hyphae Design Lab, make it extremely water efficient. It is irrigated mostly by captured storm water and condensation from the building’s HVAC (climate control) system. Any runoff from the wall is captured and recirculated. And moisture sensors monitor the wall continuously, so irrigation occurs only when and where it’s needed.

Habitat Horticulture invented the special geotextile in whose cut pockets the plants live. It is made of recycled plastic bottles and other sustainable materials, Brenner explains, “and it’s engineered to encourage growth, hold water, and drain correctly. It’s ideal for growing vertically.” As the plants grow and their roots engage the textile more and more, less soil will be needed, reducing the installation’s overall weight.

According to Kaufman, the massive size of the wall was not about grandiose aspirations of largeness, but rather about seizing the opportunity to use an available space for something spectacular and visitor friendly. “That garage wall was for us sort of a found canvas. We asked ourselves, ‘How can we take advantage of something that is already here and make it better?’ We weren’t thinking of the living wall as a work of art, but more as part of the architectural experience.”

Brenner, for his part, absolutely thinks of his walls as art. “Every planting area, each swath on the wall, the colors, the species, the flowering time—everything is there for a specific reason, both aesthetic and functional.”

Brenner’s walls are also like his children, in that they require constant attention. “We can definitely train a person to maintain the system, but no one can know it as well as we do. Plus, every wall is different and has its own challenges: understanding how the plants should grow, and changing the irrigation and fertilizer allocations based on continual observation. The large ones I like to visit at least once a week, to make sure all the plants are happy.”