Fact Sheet

The University of Washington Botanic Gardens (UWBG) is part of the School of Environmental and Forest Sciences in the College of the Environment.

The Botanic Gardens’ name was established in 2005 to unite the gardens and programs of the Washington Park Arboretum and the  Center for Urban Horticulture and is located around the shoreline of Union Bay on Lake Washington.

UWBG Living Plant Collections contain over 13,900 specimens representing over 4,000 distinct taxa. 2,308 accessions are of known wild origin.  More than 40,000 exotic and native plants are found in the Washington Park Arboretum alone.

The 230-acre Washington Park Arboretum (WPA) is one of the most important tree collections in North America. It is jointly managed by UWBG (plant collections) and the City of Seattle’s Department of Parks and Recreation (park functions), with support from the Arboretum Foundation. WPA is in the top five national arboreta and botanic gardens collections in maples, magnolias, Pine family, hollies, mountain ash, oaks and viburnums.  The UW Botanic Gardens is member of the Plant Collections Network (PCN) – administered by the American Public Gardens Association and the US Department of Agriculture – which recognizes official North American collections.  We have PCN collections for Acer (maples), Magnolia, Ilex (hollies) and Quercus (oaks).

All parts of the Washington Park Arboretum, with the exception of the Japanese Garden, are open to the public free of charge.

The 16-acre Center for Urban Horticulture site serves as the meeting place for horticultural groups. The Center’s Merrill Hall is the first sustainable building to be built on the UW Seattle campus. It houses our administrative offices and research labs, the Miller Library, and the Hyde Herbarium. It also provides space to the WSU King County Extension Program and the Master Gardener Foundation of King County. Gardens at the Center contain over 150 woody plant species and cultivated varieties and nearly 500 herbaceous perennials.

The Center for Urban Horticulture also includes the 74-acre Union Bay Natural Area. With four miles of shoreline, it serves as an outdoor laboratory for UW research and as a publicly accessible wildlife habitat.  More than 200 bird species have been sighted in UBNA.

The Elisabeth C. Miller Library is one of the most important horticultural libraries in North America. It houses 15,500 books, 500 journal and periodical titles, 1000 nursery catalogs, and video and electronic resources. It offers a range of free services to the public and the academic community. The annual Garden Lovers’ Book Sale is held in early April.

The Otis Douglas Hyde Herbarium houses over 23,600 specimens from the Washington Park Arboretum and elsewhere and is one of the nation’s largest collections of preserved specimens of cultivated plants. It serves as the official herbarium for the Washington State Noxious Weed Board and also provides free plant identification help to the public.

The Botanic Gardens emphasize sustainable practices throughout our programs. In addition to composting, recycling, and using electric work carts, we boast the first LEED-certified building on campus, practice Integrated Pest Management, and contribute to UW’s Salmon-Safe certification.

Number of People who visit annually (Admission is free): 320,000 (250,000 to the Arboretum; 70,000 to the Center), 98% are from Washington State.

Undergraduate Participation
  • Restoration Ecology Network: 500 students and 34 community partners
  • School of Environmental and Forest Science classes at UW Botanic Gardens: 12
  • Regional Community College horticulture programs: 3
Graduate Students: 36
Elisabeth C. Miller Library
  • Annual number of visitors: 20,000
  • Annual number of books checked out: 7,000
  • Annual website pageviews 118,000
  • Annual number of reference questions researched and answered: 5,000
  • Children Programs, Classes, Exhibit Openings, and Tours: 200 events/groups, 2,000 participants
Educational Programs
  • Youth Saplings School Programs: 384 programs; 5,767 participants
  • Family Programs (parent & child classes, night hikes): 138 programs, 1,979 participants.
  • Explorer Family Pack Rentals: 11; 188 participants
  • Youth Day Camps: 7weeks of camp; 299 participants (includes Spring Break Camp)
  • Fiddleheads Forest School: 24 enrolled students
  • Adult Public Programs and Classes: 330 participants, 36 programs
  • Adult Professional Programs: 25 programs, 1100 participants
  • Adult Tours: 59 tours; 779 participants
  • Subscribers to E-Flora, the monthly newsletter, unit newsletters and other social media: 13,191
  • Annual website pageviews: 562,479
  • Annual number of Rental Events: 1,800
  • Volunteer participation is essential to the Botanic Garden success & vitality
Research Programs
  • The Washington Rare Plant Care and Conservation Program partners with 25 federal and state land holding agencies to monitor 900 rare plant populations. In 2003, the Miller Seed Vault was built at UWBG. It is the only state-of-the-art climate controlled storage and lab facility for seeds of Washington’s rare plants and currently stores seeds of 107 rare Washington species and has received 69420 accessions (seed lots).
  • Biology of invasive species, including assessment of invasive potential of introduced plants and impacts of current invaders
  • Propagation of rare species for reintroduction into the wild
  • Biology of rare plants
  • Restoration ecology research (collaboratively with the Restoration Ecology Network), using the Union Bay Natural Area as its outdoor laboratory.  UW-REN involves undergraduate students in research through a restoration capstone course that, since its inception, has completed 50 collaborative restorations in western Washington.
  • Plant responses to climate change and other ecophysiological studies of plants
Other Affiliated Research
  • Human dimensions of urban forestry & urban greening
  • Human response to land use change along the urban to wildland gradient, and the relationship between forest lands and the built environment
  • Forest soil microbiology (especially decomposition, nutrient cycling processes, and mycorrhizae) and forest pathology (especially root and canker diseases)
  • Host selection behavior of bark beetles; aquatic entomology; and tropical forest insects
  • Tissue to whole tree responses to environmental stresses, particularly in water and nutrient relations, carbon economy, and growth of trees from diverse ecosystems

Frequently Asked Questions

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