A horse-chestnut tree (Aesculus hippocastanum) has taken center stage in the design of an assisted living and memory care center project in Covington, Washington. Lovingly referred to as Horsey by the project design team, the nearly 50-year-old tree stands at the center of the 3-acre site, which was previously a plant nursery.

The healthcare developer, Roundlake Development, was set on preserving Horsey from the beginning. They worked with the rest of the site design team, including Principal Landscape Architect Chris Overdorf, to design the entire 4-story, 80,000-square-foot assisted living facility around the tree.

With the building’s foundation most likely beginning to impact Horsey’s roots, special care was needed to ensure the tree survived. So nearly two years ago, Chris began working with the construction crew on a plan to preserve Horsey through the construction process and minimize activities that could negatively impact the tree’s health.

First, Chris worked with the contractor to trench around Horsey’s drip line in several successive steps to surgically trim back the tree’s roots. Each time they trimmed back the root system, they pruned some of the canopy to compensate. Then they gave it as much water as it could take in.

“The care we’re putting into the tree is a reflection of its importance to the client, as well as its benefit for future residents of the assisted living center,” said Chris. “A new tree would take 40 years to mature. Horsey will help connect them to the landscape as soon as they move in, providing shade, companionship, and beauty, as well as a connection to history and a sense of belonging.”

The foundation footings for the care center were laid a few months ago, and considering how impactful construction can be on trees, Horsey is responding very well. When Chris visited the site the first week of March, the tree was revealing thousands of opening buds. Trees have become so central to the site—which has 54 more than required by code—the City has joked that the project team is “replanting a forest.”

The Covington project is one of many assisted living and memory care centers Chris has worked on with Roundlake. With each new project, the goal remains the same: to create healthy outdoor spaces that engage and support residents.

Because physical activity improves cognitive health and helps slow brain attrition, walking paths are a central feature of every one of the projects. At the adjacent memory care center, a central courtyard with two intersecting figure-eight paths is being built for residents, providing them a secure route with lots of sensory stimulus.

The center of the path is filled with a variety of plantings to engage senses and spark fading memories—tulips, daffodils, lilies, pansies. The garden is designed to always be changing, with something blooming spring through fall. Art, birdhouses, lighting, forms, scents, and textures are other design elements Chris and the team incorporate to stimulate memory recall for residents.

“With each of the assisted living and memory care centers I help design,” said Chris, “I’m guided by the thought, ‘If my mom had dementia, this is where I would want her to be.’”

Last year, Chris planted a few saplings grown from Horsey’s seeds in his yard. Another grows in a client’s yard in Seattle.