History of the Arboretum

Arboretum Turns 90 in 2024!

Our beloved Washington Park Arboretum will celebrate its 90th anniversary in 2024. To mark the occasion, we are planning a series of festive events, beginning with our Birthday Birthday Bash Opening Night Party on February 13, 2024. Join us to salute 90 remarkable years!

A celebrated Olmsted park and botanic garden

Washington Park Arboretum has a long and complex history. Prior to white colonial settlement, the land was home to Coast Salish people, who had several villages in the Union Bay area. Towards the end of the 19th-century, it was owned by the Puget Mill Company, which logged the land’s large trees in the 1880s. In 1900, the site became a city park, Washington Park (one of Seattle’s first), and was home to a speedway for horse racing and a sanitary fill.

In 1903, the Olmsted Brothers Landscape Architects firm created the design for Lake Washington Boulevard, which weaves through to present-day Arboretum, as part of its comprehensive plan for Seattle parks and parkways. Washington Park remained largely undeveloped in the 1910s and 1920s.

Strollers on Azalea Way, 1957. Photo by John Valentine, Courtesy MOHAI (1986.5.15741.1)

Interest in creating an Arboretum in Seattle had been brewing for three decades among staff at the University of Washington and members of the community. The Arboretum was officially established in 1934. The following year, the Arboretum Foundation was formed to raise funds for the nascent botanical garden. In 1936, thanks to a donation from the Seattle Garden Club, the Olmsted Brothers were hired to create a design plan.  

With the Great Depression in full swing, much of the early construction and planting work in the Arboretum was carried out through the Works Progress Administration. The speedway became Azalea Way, one of the central features of the Arboretum. In the decades to come, especially under the tenure of Brian Mulligan (director from 1945 to 1972), the Arboretum’s plant collections developed, flourished, and grew to what you see today.

Further Reading

  • HistoryLink, a free online encylopedia of Washington State history, also published an excellent short history of the Arboretum in January 2013.
  • Read a detailed historical review (PDF 12.0 MB), commissioned by the Arboretum and Botanical Garden Committee in 2003 and co-authored by BOLA Architecture & Planning and Karen Kiest Landscape Architects.
Guests Shower the Arboretum with Birthday Love at Opening Night

Guests Shower the Arboretum with Birthday Love at Opening Night

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...

Our Marvelous Mountain Hemlock

Our Marvelous Mountain Hemlock

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...

New Plantings in the Arboretum: 2023 in Review

New Plantings in the Arboretum: 2023 in Review

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...

Ginko Biloba

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