• 1800's: Current site of the Yakima Area Arboretum existed as riparian wetlands.
• 1940's: Site used as a vegetable farm. Jack Takayama, future Garden Landscape Architect of the Japanese Garden, used to work as a farmhand here. It is rumored that Senator Alex Deccio may have also worked the farmland here as a boy.
• 1967: Current site was seen as best area for an arboretum. Yakima Area Arboretum was incorporated. Landscape architect Robert Wagner of Spokane drew a master plan for the first 16 acres of development. Projected cost was $56,000-65,000.
• 1967: The Arboretum's first tree, a Cedar of Lebanon, was planted on Arbor Day. The tree did not survive.
• 1968: Money was raised through a fundraising drive and a tree seedling sale. The garden clubs raised $3,000 through sales of a gardening wisdom book called "Did You Know?" The garden clubs also solicited memberships, donations, and memorials, and held a holiday show and plant sale.
• 1969: Much progress was made as the land was cleared and contoured, well drilled, irrigation system installed, 500 pounds of grass seed planted, and fifteen different species of evergreen planted. There was an agreement in place that the City of Yakima would take over maintenance once the Arboretum was fully developed.
• 1976: The Japanese Garden was started through the efforts of Phil Jenkins and Yoshio Hata. Designed by Jack Takayama, the garden was built with assistance from Central Pre-Mix, the Oak Creek Game Departement, and the Army national Guard. A hand-carved stone lantern, a gift from Yakima's sister city in Japan, was added the following year.
• 1970's: The maintenance agreement between the Arboretum and the City of Yakima is amended with the realization that the Arboretum is an ongoing project, development of which would never be fully completed.
• 1980's: Yakima Greenway Foundation was created; the organization built a pathway through the Arboretum's natural area. The Arboretum also granted permission for the Greenway Foundation to add picnic tables in the southern corner of the grounds.
• 1982: Gilbert Rhody and Azalea Garden was funded and installed in the evergreen area. The garden was moved to the wetlands for increased shade and water two years later.
• 1985: The Arboretum was officially dedicated on May 18.
• 1987: Wilma Walker donated $10,000 toward renovation of the barn. Since the barn was so far outdated and a new one should be built, the funds were dedicated to a library in the new building.
• 1989: Robertson Charitable Trust donated $25,000 which was used to create a "floating endowment." A volunteer architect drew plans for a new visitor center. Don and Helen Jewett donated $50,000 to contour, irrigate, and seed the 11-acre Jewett Addition. Jewett Pond was created the following year.
• 1991: Don and Helen Jewett made a $500,000 donation to build the Jewett Interpretive Center.
• 1992: The big holiday tree was lit for the first time; Luminaria walks began thanks to the efforts of the Cascadians. Conversations began with Fred and Dorothy Plath that eventually led to construction of the Plath Solarium as a rentable addition to the Jewett Center.
• 1993: The agreement between the City, Arboretum, and Greenway was revised to include the six-acre Shields addition. An annuity of $225,000 was received following the death of Don Jewett. Our Japanese sister city planted ten Yoshino Cherry trees at the entrance to the Japanese Garden.
• 1994: The Jewett Waterfall Garden was dedicated on Arbor Day. The Plath Solarium was dedicated at the Arboretum's Annual Meeting. The Fresh Science program was developed for school tours in conjunction with WSU Master Gardeners, Heritage College, Yakima County Solid Waste, and the Washington Native Plant Society.
• 1995: The community donated $30,000 to install a sign along the highway. Planning began to build the Harold Jones Nursery Center. Hata Gateway in the Joyful (Japanese) Garden and the compost demonstration sites were both dedicated.
• 1996: The Schroeder Wetland Trail on the east side of the Arboretum grounds was completed and dedicated.
• 1997: Buchanan Lake on the north side of the Arboretum grounds was filled.
• 2001: The Heritage of Trees Exhibit opened inside the Jewett Interpretive Center.
• 2002: The first annual Autumn Bounty was held in September. The fundraising event raised $13,000 for the Arboretum.
• 2002-2003: The Xeriscape Demonstration Garden and straw bale wall were built near the Jones Center, thanks to a collaboration between Yakima county Solid Waste, Department of Ecology, and the Arboretum.
• 2003: Lower Naches Garden Club expanded the Arboretum's rose garden.
• 2004: A grant was received from Yakama Nation Legends Casino to expand the Fresh Science curriculum. The "Plant a Tree! Help us Grow!" fundraiser for Arbor Day raised enough money to plant 18 trees and shrubs on the Arboretum grounds. Southwest Rotary, in commemoration of 100 years of Rotary International, donated the Centennial Pagoda. The Pagoda is located in the Joyful (Japanese) Garden.

Thanks to the many volunteers who combed through past newsletters, records, and board meeting minutes to compile this history!