Legacy Family Birth Center Garden fountain / Brian Bainnson

Among hospital administrators, there seems to be a growing concern that therapeutic gardens can harbor diseases and spread them to those who have compromised immune systems. There was a case of Legionnaire’s disease spread through a water fountain, and soils can also be a source of some illnesses, but the fears are essentially unfounded, argued a trio of landscape architects at the Environments for Aging conference in Las Vegas. Good design and maintenance can eliminate the risks.

Leah Diehl, director of therapeutic horticulture, the Greenhouse at Wilmot Gardens, college of medicine at the University of Florida, said landscape architects should use “evidence-based knowledge to counter fears.” The evidence points to the incredible health benefits of being in nature. As such, the proven health benefits of “seeing, hearing, touching water” found in a fountain — such as reduced stress, lower heart rates and blood pressures, and an increased sense of tranquility — outweigh the near-zero chance of catching something. In terms of soils, yes, there are toxic bacteria that naturally occur in the mix, but there’s also mycobacterium vaccae, which some scientists think can play a role in reducing the effects of depression and anxiety.

For landscape architect Brian Bainnson, ASLA, “proper design can disrupt the process of infection.” For an infection to occur, there needs to be a pathogen, a susceptible host, and a mode of transmission. He argued that the Legionella bacteria, which causes Legionnaire’s disease, is more often spread through HVAC systems, spas, and jacuzzis than fountains. He said a “lack of maintenance allows the pathogen to grow.” He also said “there is no documented evidence of an infection from a healthcare garden.”

Glenbrook Hospital fountain / AIA

For a healing garden at the Legacy Emanuel Medical Center in Portland, Oregon, he designed a water feature with an integrated design team of physicians, therapists, hospital administrators, and maintenance workers to ensure there was no standing water when the fountain is off, and that patients can’t easily touch the water (see image at top). “Removing standing water is also good for vector control,” meaning it reduces places where mosquitoes can breed.

For another garden in the oncology ward of a hospital, Bainnson recommended administrators install Ultraviolet (UV) or flouridation systems to ensure the water is clean. It’s important in these instances to work with the maintenance staff to make sure those filters are tested and cleaned regularly.

For him, “the benefits of the fountains are too high, and they should outweigh any perceived risks.”

Diehl offered other examples: the Evanston Hospital in Illinois, which has a three-story fountain wall that ends in a pool, use sand filtration and chlorination and tests regularly to ensure the highest levels of water quality. And at the Glenbrook Hospital, also in Illinois, there is an entire water management team charged with infection control that tests the water in their fountains each month.

Jack Carman, FASLA, a landscape architect who focuses on senior care facilities, talked about the potential dangers of flora in therapeutic gardens, arguing that “not all plants are safe.” He said when using a plant in a healthcare setting, it’s important to know if “it’s toxic and highly injurious.”

It can get complicated because some plants may be only mildly toxic, or both medicinal or toxic depending on the interaction. For example, juniper has a medicinal use but its berries are toxic in large amounts. And some other plants are questionable, like daffodils, which are safe, but have toxic bulbs.

But there are some straight-out dangerous plants, like Foxglove, that shouldn’t be in therapeutic gardens. “Also, azaleas and rhododendrons don’t belong in a garden for Alzheimer’s patients.” Plants with extremely sharp edges, like hollies, or thorns, like rose bushes, obviously shouldn’t be found near where anyone is walking.