COENOSIUM ROCK GARDEN is a verdant escape in the heart of our city.

Set within the arboretum on the South Seattle College campus in West Seattle, about 6 miles from downtown, the thoughtfully designed landscape is home to one of the top conifer collections in the nation. The garden also is a living laboratory where students in the school’s horticulture program can hone their developing landscape construction and management skills.

The Arboretum at South Seattle College

More information

What: The Arboretum at South Seattle College

Where: 6000 16th Ave S.W., Seattle.


“Coenosium” means community of plants. Likewise, creating the garden has been a collaborative effort among a community of working professionals and those just getting started in horticulture.

Back in the mid-1990s, Steve Nord, an instructor in the expanding horticulture program at what was then called South Seattle Community College, was interested in adding a dwarf conifer garden to the growing arboretum. Nord reached out to local nurseryman Bob Fincham and his wife, Dianne, who owned a nursery called Coenosium Gardens that specialized in dwarf conifers. “Dianne and I have always valued education,” Fincham tells me. “We agreed to work with Steve and the college to donate a dwarf conifer garden, provided the bulk of the work was performed by students as part of their educational program.”

In 1999, Yukai Kato, a student in the landscape design program, developed the elevations and hardscape for an undeveloped acre in the arboretum at the north end of campus. The Finchams took the lead on planting design, focusing on showcasing choice dwarf and miniature conifers that were available from specialty nurseries but less well-known in the general marketplace.


Along with the Finchams, Rick Lupp of Mt. Tahoma Alpine Nursery and the North American Rock Garden Society generously supported the developing garden. The garden was laid out and planted by students over the course of several years and was publicly dedicated in the spring of 2005.

Today, Coenosium Rock Garden is an elegant public garden and a peaceful sanctuary. A 200-foot-long border densely planted with deciduous trees and conifers buffers noise from the adjacent busy street and shelters the interior garden, a hushed space where all you hear is the crunch of your footsteps on the gravel pathway, and birds. Planting beds and berms filled with more than 300 unusual conifers reflects the focus of the garden’s plant-driven design. Tall columns contrast with mounding hummocks and weeping forms. Silver, blue and olive needles, scales and fans introduce texture and contrast. With towering elders and carpeting ground covers, this is a layered landscape. You might be surprised to discover “dwarf” doesn’t necessarily mean small.

Japanese maples and other deciduous trees mixed among massive granite boulders and rocky scree leaven the landscape, introducing light and empty space to what could easily have become a dense, ponderous planting. A naturalistic cascading water feature animates the wooded environment with sound and glittering reflections.

Coenosium Rock Garden was inducted into the Gardens for Peace program in 2010, and The American Conifer Society recognized the exemplary collection as a public reference garden in 2014. The arboretum is open every day from dawn to dusk. A searchable list of plants in the Coenosium Rock Garden can be found on the arboretum’s website.