Stress reduction and other wellness benefits from encounters with the healing power of nature have been well documented. But is evidence for these therapeutic benefits sufficient to persuade hospitals to invest in gardens and green spaces for the benefit of their patients and staff?

For the past eight years, a research team at the 485-bed Legacy Emanuel Medical Center in Portland, Ore., has applied rigorous methods of medical research to capture clinical outcomes from visits to the hospital’s Terrace Garden, by patients, families, and nursing staff.

The 6,800 square-foot-garden was built on an underutilized second-floor roof space located just outside the cardiovascular ICU and near the family birthing center, facing the hospital’s interior courtyard. The garden, adjacent to a long hallway offering clear garden views even in inclement weather, includes benches, chairs, and tables (some movable to a variety of configurations); user-friendly pathways; a children’s playhouse; and a water feature. But more than half of the space is devoted to a profusion of greenery planted around the four seasons.

Work on the garden was completed in 2014 with a $558,000 grant from a program of the TKF Foundation (Annapolis, Md.), which guides communities in the creation of public green spaces. The grant supported both the garden’s construction—including some structural reinforcement of the terrace—and the medical research, led by co-principal investigator Roger Ulrich, a pioneer of evidence-based design in healthcare and since-retired visiting professor in the department of architecture and Center for Healthcare Building Research at Chalmers University of Technology (Gothenburg, Sweden).

The goal was to measure and document clinical outcomes from nature access in the garden for three distinct populations: family visitors whose loved ones were having extended stays in the ICU; critical care nurses, who may be prone to job stress and burnout; and expectant mothers in the birthing center and their partners. But the researchers faced significant methodologic challenges. For example, both the nurses and the expectant mothers resisted participation in randomized controlled trials because that meant they could be assigned to the non-garden-access control group. Sufficient sample size was another challenge.

“We had a lot of discussions (about research methods), from pretty rigorous measures like the level of cortisol in saliva down to observational studies,” says Makayla Cordoza, a nurse and now a postdoctoral fellow in the department of psychiatry at the University of Pennsylvania Perelman School of Medicine (Philadelphia). Cordoza joined the research team as a representative of clinical practice nursing and brought her interest in health and burnout of working nurses.

Because the Legacy researchers could not do randomized controlled trials, considered the gold standard of medical research, the team adopted self-reported qualitative studies using validated measures on voluntary subjects asked to fill out questionnaires and observational studies by researchers watching from a distance how the gardens were being used.

Studies were conducted between 2011 and 2019 and the results have started to appear in medical journals. For example, one finding from the research was that access to an unlocked garden with abundant nature located close to the ICU significantly mitigated the stress experienced by family visitors, which has been compared to post-traumatic stress disorder. Critical care nurses who took daily work breaks in the gardens had reduced rates of sadness, anger and fatigue. And full-term, low-risk expectant mothers at the hospital’s birthing center—and their partners who utilized the garden during the hospital stay—found the garden beneficial and increased their satisfaction with their care.

“The research confirmed what we already knew anecdotally—that the garden space is beneficial to all—staff, patients, and visitors who spend time there,” says Bridget Martin, a nurse leader in the neurotrauma ICU at Legacy Emanuel and a member of the research team. “Interestingly, it didn’t require spending a lot of time in the garden to gain its benefit. Just passing through the garden for a few minutes can decrease stress levels.”

A fourth study, in review for publication, used behavioral mapping techniques to observe what people were actually doing in the garden, including meditating, looking at plants, eating, talking, or just sitting. Whether these different activities might affect the restorative benefits of the garden is a target for future research, Cordoza says.

Structural components of a healing garden

Building on the success of the Terrace Garden, one of 12 gardens built since 1991 and strategically placed across Legacy Health’s six hospital campuses, there are several takeaways and ideas for healthcare facilities looking to add or expand healing gardens on their grounds.

The Legacy project was designed based on principles of evidence-based design, including research on how people respond to space. Legacy’s design teams also drew upon the seven characteristics of a therapeutic garden, adopted by the American Horticultural Therapy Association in 1995, including scheduled and programmed activities, features modified to improve accessibility, well-defined perimeters, and a profusion of plants and people/plant interactions.

Multidisciplinary teams, including clinicians and managers of the relevant hospital units as well as patients, family members, facility managers, a landscape architect, and others, are essential to the success of design, planning, evaluation, and programming of the gardens, says Teresia Hazen, coordinator of the therapeutic garden program at Legacy Health and a registered horticultural therapist.

In addition to the right team, a well-designed hospital garden starts with its structural components, including pathways that are navigable and smooth, says Kathleen Wolf, research social scientist in the College of the Environment at the University of Washington (Seattle) and former advisor to TKF garden initiatives, including the one at Legacy Health. “Then you need a mixture of shade and sun. There should be evidence of enclosure and a sense of security, with a portal that conveys a clear understanding of where you enter the garden.”

Therapeutic gardens should be located close to their targeted populations and kept unlocked, open, and safe 24 hours a day, Wolf notes. Paths should be accessible to users with limited mobility, including those who use crutches, walkers, or wheelchairs. Additionally, an informal, natural style is more effective than formal spaces that have less nature and more hardscape, Hazen says. Some protection from the weather is helpful, as is offering both social and solitary settings, with opportunities for privacy for both caregivers and staff.

Legacy Health is unusual in having so many healing gardens designed for individual user populations—with their different treatment and therapy needs—which is supported by research with children, mental health patients, and others, Wolf says. “If planning a hospital garden, why not think about these different needs and be opportunistic?”

Another key to leveraging garden spaces on a healthcare campus is the use of programming, both structured and unstructured events (with educational signage to promote independent use). For example, the gardens at Legacy Emanuel are used for patient therapies and have hosted “Midnight in the Garden” events for night staff, pet therapy, garden tours, musical performances, mindfulness classes, organic gardening, birding, and, in past years, Earth Day celebrations.

Beneficial to all

In a time of unprecedented stresses on our healthcare system and society due to COVID-19, the importance of gardens as peaceful sanctuaries and as therapeutic interventions to relieve stress is greater than ever. Dr. Minot Cleveland, a former emergency physician and Legacy’s medical director of employee health, says Legacy’s garden program is central to its efforts to promote employee health and well-being.

Physicians and clinicians seem to appreciate that there’s now evidence that taking work breaks of even just 20 minutes significantly reduced signs of burnout in nurses working in high stress environments, he says. “Even before COVID-19, issues of burnout and turnover in the workplace—and not just in healthcare—were getting more attention. Now the idea of health benefits for our workforce takes on greater importance as people’s stress levels and mental health issues come to the fore. The advantage of our research data is that it could help overcome some people’s skepticism to the idea that nature access in gardens really is valuable,” he says.

“I get pretty passionate about the benefits of our gardens,” he adds. “Part of our message is that this is doable for other health facilities, even if not on our scale.” Start small, he says, and encourage staff to take breaks and to get outside. “Now more than ever we need all the tools to help us get through these challenging times.”

Larry Beresford is a freelance medical journalist based in Oakland, Calif. He can be reached at