The Rhododendron Species Foundation is a non-profit organization founded and incorporated in 1964 by members of the American Rhododendron Society in order to secure the finest authentic forms of Rhododendron species, and to develop a comprehensive collection of this plant genus. Conservation has become of primary importance in recent years due to the destruction of Rhododendron habitat in many areas of the world. 

Following initial discussions among Rhododendron breeders and enthusiasts in the Pacific Northwest, the real origin of the Rhododendron Species Foundation may be said to lie with a visit to England by Dr Milton Walker in March of 1964.  The purpose of his visit was to explore the possibility of importing cuttings of the best forms of Rhododendron species growing in both public and private British gardens, many from the original wild collections.  Among the gardens he visited were Windsor Great Park, Wakehurst, Leonardslee, and the major Cornish gardens, including Caerhays.  In September he wrote to these gardens, as well as to Brodick, Wisley, Corsock, Leggygowan (Northern Ireland), Glenarn, Logan House, Younger Botanic Garden of Benmore, Stronachullin, and the Royal Botanic Garden in Edinburgh, to request cuttings.  But there was a problem.  Due to American import regulations the cuttings could not be brought into the United States directly from Europe.  They could, however, due to an extraordinary flexibility on the part of the Canadian Department of Agriculture and Canada Customs, be imported into Canada.  Dr. Walker contacted Mary Grieg, owner of the Royston Nursery on Vancouver Island, to inquire if it would be possible for the cuttings to be imported and propagated in British Columbia.  As a result of Mary Grieg’s further inquiries, arrangements were made with the University of British Columbia, and the first shipment of cuttings arrived there from Brodick Castle in September, 1964.  Subsequent  shipments arrived in Vancouver that same fall, and over the next several years from other major British gardens. At UBC they were propagated by Evelyn Jack (now Weesjes), who in the process took on much of the correspondence with the British sources.  The plants were grown on for up to two years, and, with a sharing agreement providing that one plant of each selection be kept at UBC, then sent on to Oregon to become a permanent part of the RSF collection. 

The RSF Rhododendron collection was first housed on Milton Walker’s property at Pleasant Hill, near Eugene, Oregon. The first plants were sent there in October, 1968. Three years later the collection was moved to the property of RSF board member P.H. (Jock) Brydon, near Salem, Oregon. By the fall of 1973 it had become apparent that the collection was becoming too large for the Brydon property, and a committee met with George Weyerhaeuser (a relative of committee member Corydon Wagner), who was immediately and enthusiastically receptive to the idea of providing space on the new Weyerhaeuser corporate campus. In 1974 the Weyerhaeuser Company generously leased at no cost a permanent site of 24 acres for the collection at its corporate headquarters in Federal Way, Washington. The collection was relocated from Salem to the Federal Way site in 1975, and planted in accordance with the geographic area of species origin.

A membership program was started in 1976, and has representation from 15 different countries.  Plant distribution to members was also begun about this time, with the profits helping to support the garden. 1980 marked the opening of the Garden to the public on a limited basis, the formal establishment of a coordinated volunteer program, and the completion of a garden master plan that proposed replanting the collection in the Garden to reflect taxonomic groups (those species that are most closely related are planted near one another).  This replanting was completed in 1984.

Education has always been a primary goal of the RSF. An International Rhododendron Species Symposium, organized by the RSF, was held in Tacoma, Washington, in April, 1985.  Another long-held educational practice of the RSF is to provide horticulture students with practical hands-on experience. The Student Intern Program was inaugurated in 1986.  Since that time 52 budding horticulturists have worked and studied in the Garden and nursery.