Volunteers working in the Holly Collection area during Earth Day 2024. About 180 volunteers attended our annual Earth Day at the Arboretum work-service event on Saturday, April 20. They worked all morning under the supervision of the UW Botanic Gardens horticulture staff, with logistical support from Seattle Parks and Rec, to remove invasive weeds from natural areas and collection beds, and to spread protective mulch—donating 540 volunteer hours to the park! As part of the Arboretum’s 90th birthday celebration series, the volunteers enjoyed cupcakes at the Graham Visitors Center at the end ..read more

Workers demolishing the ramps in late winter, 2024. (Photo courtesy WSDOT) From February to mid-April 2024, construction crews on the SR 520 Bridge Replacement Project used enormous excavators to demolish the final remnants of the so-called “ramps to nowhere” on the WSDOT Peninsula at the north end of Washington Park Arboretum. WSDOT is currently using the peninsula as a staging area for the bridge replacement project. The ramps were constructed in the early 1960s to connect the SR 520 to the R.H. Thomson Expressway, a planned north-south highway that would have cut through the east side o ..read more

Workers demolishing the ramps in late winter, 2024. (Photo courtesy WSDOT) From February to mid-April 2024, construction crews on the SR 520 Bridge Replacement Project used enormous excavators to demolish the final remnants of the so-called “ramps to nowhere” on the WSDOT Peninsula at the north end of Washington Park Arboretum. WSDOT is currently using the peninsula as a staging area for the bridge replacement project. The ramps were constructed in the early 1960s to connect the SR 520 to the R.H. Thomson Expressway, a planned north-south highway that would have cut through the east side o ..read more

Camellias can provide a colorful alternative to the ubiquitous English laurel hedge. (Photo: Chris Pfeiffer) Despite being old-fashioned, hedges remain popular with home owners because of their ability to provide privacy, block unsightly views, add beauty to the garden, and yield a variety of ecological benefits. In gardening times past, choices for hedging plants were limited to a small selection of plant species, such as English laurel and boxwood. Nowadays, better options abound. In the latest issue of the Arboretum Bulletin, plant experts Christina Pfeiffer and Walt Bubelis provide a s ..read more

Harlequin flowers (Sparaxis species) by Arabella Roupell, from “More Cape Flowers by a Lady.” In the latest issue of the Arboretum Bulletin, manager and curator of the Elisabeth C. Miller Library Brian Thompson continues his series of book reviews focused on women botanical artists and botanists.  In part 6 of the series, he writes about five pioneering British botanical artists of the 20th century: Matilda Smith, Lilian Snelling, Arabella Elizabeth Roupell, Elinor Frances Vallentin, and Harriet Isabel Adams. Learn about their lives and the books they published, and then visit the Mil ..read more

Party guest posing with some fairie folk during the show garden preview.  A total of 325 guests attended our annual Opening Night Party at the Northwest Flower & Garden Festival on February 13 and helped us raise more than $425,000 in support of core programs at the Washington Park Arboretum. This year’s party marked the 90th year of the Arboretum (1934–2024), and guests joined with us for a BIRTHDAY BOTANICAL BASH to celebrate the past, present, and future of this beloved green space. The evening began with a champagne reception in the 4th Floor Atrium of the Seattle Convention C ..read more

The mountain hemlock cultivar ‘Bump’s Blue’ growing in the Arboretum. (Photo by Niall Dunne) Mountain hemlock is an incredible species, able to grow in an environment where conditions alternate between deep winter snows and harsh summer dry spells, and where growing seasons can sometimes be measured in mere weeks. In subalpine forests of the Pacific Northwest, the tree provides food and habitat for numerous animal species. Because of its toughness, it also adapts well to the urban landscape, where it is prized for its compact habit and fine-textured foliage. Several cultivars of the tree a ..read more

Rhododendron pubescens in bloom in lower Rhododendron Glen. (Photo by Niall Dunne) In the latest issue of the Arboretum Bulletin, UW Botanic Gardens Curator of Living Collections Ray Larson writes his annual, in-depth review of new plantings in the Arboretum. Ray focuses primarily on the many new trees, shrubs, and perennials that were planted along the newly restored streambed in the mid- to lower Rhododendron Glen in early 2023. Exciting additions to the collection include several species of large-leaved magnolia and three specimens of Rhododendron pubescens, a species that’s vulnerable ..read more

Volunteers Lily Takatsuka, Judy Phillips, and Lois Prestrud mounting specimens for the Hyde Herbarium. (Photo by Eve Ricenbaker) The Otis Douglas Hyde Herbarium at the Center for Urban Horticulture houses the largest collection of horticulturally significant dried plant specimens in the Pacific Northwest. It is a valuable resource for plant research, supporting studies in taxonomy, paleobotany, insect ecology, climate change, and more. A vibrant community of volunteers support the work of the herbarium and has done so since the early 1970s, when a group of Arboretum Foundation volunteers f ..read more

Fall foliage and flower buds on a Japanese spicebush in the Arboretum’s Woodland Garden. (Photo by Niall Dunne) Native to Japan, Korea, and China, Japanese spicebush (Lindera obtusiloba) is a stellar, all-season showstopper. Around mid-March, its bright-yellow, star-shaped flowers emerge in lavish quantities from the bare stems, providing a welcome contrast to the often-dour weather days. Its large, aromatic, and polymorphic (differently shaped) leaves provide opulent texture and shade—and they turn a rich, buttery yellow in fall. Shiny, black fruits and large, round, yellow-to-red flower ..read more