“Let’s be clear,” Cooper Marcus says. “Spending time interacting with nature in a well-designed garden won’t cure your cancer or heal a badly burned leg. But there is good evidence it can reduce your levels of pain and stress—and, by doing that, boost your immune system in ways that allow your own body and other treatments to help you heal.”
Still, research shows that not all gardens are equally effective. In 1995 Cooper Marcus and landscape architect Marni Barnes received a grant from the nonprofit Center for Health Design to analyze the physical layout and daily use of several hospital gardens in northern California. In 32 hours of observations, which included taking detailed notes and interviewing users (who collectively made 2,140 visits), the researchers noticed several patterns that have been borne out in subsequent studies of other sites.
Among their findings: users mostly visited gardens seeking relaxation and restoration from mental and emotional fatigue. Tree-bordered vistas of fountains or other water features, along with lush, multilayered greenery of mature trees and flowering plants, appealed most. Those results are consistent with Ulrich’s findings of the healing power of a “window view” and also correspond with the theories of evolutionary biologists that people prefer views that are reminiscent of the savannas where humans evolved. Throughout human history, trees and water have signaled an oasis, and flowering plants have been a sign of possible food. Open views deter surprises by predators, and shaded alcoves offer a safe retreat.
The more greenery versus hard surfaces, the better. “We found that a ratio of at least 7:3 seems to work best,” Cooper Marcus says. Less greenery signals a “plaza or shopping mall courtyard” and is not as relaxing.
What you can do in the garden is as important as what you see. The results of “behavioral maps” tracking visitors’ actions while in a garden suggested a need for private conversation areas; smooth, tree-lined paths that invite strolls but that will not trip wheelchairs or intravenous poles; lightweight furniture that can be tugged into the shade or sun; and naturalistic landscaping that lures birds, squirrels and other wildlife.
One finding, in particular, surprised Cooper Marcus and Barnes. Stressed hospital employees accounted for as many visits to hospital gardens as stressed patients, and interviews confirmed that staffers depend on the greenery. “I feel like one of the Mole People,” an employee who works in the basement radiology department of a Berkeley, Calif., hospital told the researchers. She said she comes to sit amid the trees of the rooftop garden daily to relax and meditate. “It’s a big mental, emotional lift.”
Different generations seem to value the same things in gardens, but research has turned up differences, too. In 2005 clinical psychologist Sandra A. Sherman and her colleagues conducted a study of three gardens at a children’s cancer center in San Diego to try to figure out what worked and what did not. Some of the findings made intuitive sense. A mosaic turtle sculpture that small children could climb, for example, was more alluring than a crane sculpture the kids could only look at. Other results were less obvious. A riverlike water feature where kids and parents could splash and float boats together was twice as popular with the kids as a child-size playhouse that adults could not enter.
Focusing on the other end of the age spectrum, Susan Rodiek of Texas A&M has looked at long-term care institutions. In her studies, published in 2009, of a random sampling of 68 assisted-living facilities, Rodiek talked to 1,100 residents and 430 employees. “Older people,” she found, “need and benefit from outdoor space and greenery just as much as the young.”