When I want to be reminded of far-flung places, I sometimes go to Federal Way. For there, just off I-5 and tucked away on the Weyerhaeuser campus, is the Rhododendron Species Botanical Garden, a 22-acre woodland wealth of rhododendron species with origins traceable to the Himalayas, Tibet, China, Japan, Australia, and all over southeast Asia. Over 10,000 rhododendrons grace Douglas fir and bamboo thickets, meadows, alpine and pond gardens, a Victorian fern stumpery, and a new conservatory.
We're mighty familiar with rhododendrons here. Our mild maritime climate favors these shrubs, trees, and ground covers also indigenous to North America and available in hybridized forms. Anyone who's hiked in local forested parks or in the shadow of the Cascades will have encountered the Pacific Rhododendron (Rhododendron macrophyllum), the Washington state flower, with its flecked pink blossoms and leathery evergreen leaves.
And I, for one, am always overwhelmed by the mid-spring riot of rhody red, pink, and purple that erupts throughout Seattle city neighborhoods. Many of those plantings are legacies of the 1970s, an era when rhododendron selection in the Pacific Northwest was limited to middling species and bomb-proof hybrids ... well, mostly. At my house, two such relics withered on my watch, likely the result of overwatering.
But in fact the diversity of rhododendron species, or those that originate in the wild, is quite stunning. Some tree rhododendrons tower scores of feet high, while alpine forms hug the ground with their clusters of tiny flowers, wiry stems, and small leaves. The leaves of Rhododendron sinogrande measure almost three feet long. Rhody blossoms come in the colors we know well — hues of red, pink, purple, and white — but also in lovely shades of yellow and orange and in shapes of funnels, saucers, and bells.
There are even tropical species, known as vireyas, some of which grow as epiphytes in the tall trees of the cloud forest. Wild rhododendron species thrive around the globe, but Asia is home to most. And rhododendron aficionados soon learn, if they haven't already, that the most beautiful of wild species are native to Asia.
In the 1960s some members of the American Rhododendron Society (ARS) turned their attention to the wild species, but their efforts to collect true forms of the species were soon frustrated by the lack of accurate information as well as genuine specimens in the Pacific Northwest. In those days the bulk of rhododendrons verified as true species (as opposed to hybrids, or the offspring of cross-pollination between two species) was limited to British gardens.
It was the garden-obsessed British who backed the plant hunting expeditions that began in earnest in the mid-19th century with Sir Joseph Dalton Hooker and his travels in the Sikkim Himalaya. Others like E.H. Wilson, George Forrest, Reginald Farrer, Joseph Rock, and Frank Kingdon-Ward carried on the tradition of plant exploration. The seeds they painstakingly — and sometimes at great risk — collected in China, Japan, Tibet, Burma, and Thailand were sent to the British benefactors of their expeditions and then propagated in private gardens and some botanic gardens, such as Kew and Edinburgh.
In North American nurseries and gardens of the mid-20th century, the lineage of rhododendrons with Asian roots was difficult to trace. Most came from plants grown from expedition seeds propagated in British gardens. Some of these had cross-pollinated with other rhododendrons to form natural hybrids and were misidentified as species. And those that were indeed species were often inferior specimens. Clearly, there was much confusion over proper identification and a lack of authentic and superior forms of rhododendron species.
Dr. Milton V. Walker, an ARS member from the Pacific Northwest, decided to remedy the situation. In 1964 he and other ARS members in the area established a foundation with the mission to select, acquire, and propagate rhododendrons from the finest verified rhododendron species in British gardens. Walker and his wife Helen traveled to the U.K., picked the best forms from thirty private gardens and several nurseries, and ultimately compiled a list of 322 different rhododendron species or forms for the Foundation collection.
American import regulations prohibited bringing the cuttings directly to the U.S. from Europe. Instead, they were sent to Vancouver, B.C. and grown for two years at the University of British Columbia. They were established as plants in Milton Walker's garden near Eugene and later transferred to the home and nursery of another foundation member, Jock Brydon, near Salem.
Finally in 1974, after much soul searching and some anguish and through connections, the collection found its permanent home in Federal Way on donated land at the corporate headquarters of Weyerhaeuser. Truly a labor of love and obsession that is chronicled in Clarence Barrett's History of the Rhododendron Species Foundation (1994).
Today's collection in Federal Way, named the Rhododendron Species Botanical Garden (RSBG), is one of the most diverse and comprehensive in the world with 5,400 forms of more than 600 rhododendron species. Some of these species, such as the epiphytic Rhododendron edgeworthii with its fragrant pink blossoms and the early-blooming Rhododendron barbatum with its smooth exfoliating bark, were discovered by Joseph Hooker on his ground-breaking three-year expedition to the eastern Himalayas in the late 1840s.
But the tradition of plant exploration continues. A more recent introduction to western gardens growing at RSBG is Rhododendron kesangiae, a small tree of a rhody with trusses of striking rose-pink blossoms and oblong leaves almost a foot long. In 1989 it was found in the Buddhist kingdom of Bhutan and named after the then-Queen Mother.
On a visit in early May last year, I was delighted to see my favorite azalea, the Royal Azalea (Rhododendron schlippenbachii) at its flowering peak. (Azaleas, it should be noted, are classified under the genus Rhododendron.) I love this deciduous azalea, native to Korea and Manchuria, for its elegant pink blossoms and whorls of vibrant green leaves that appear after the flowers. Truthfully, I love it equally for its swashbuckling second name. Apparently, Baron von Schlippenbach, a Russian naval officer who visited Korea in the mid-19th century, was the first westerner to make a note of the plant in the wild, and so it was named after him.
Peak rhododendron bloom season is March through May, but even if rhodies aren't your cup of tea, the array of companion plants throughout the garden should be eye candy enough. There are hardy and deciduous ferns, perennials such as Iris and primroses, heathers, Japanese maples, conifers, and magnolias. One spring I happened upon a drift of Himalayan blue poppies, a magical experience indeed.
Last year the memory of that otherworldly blue, and of my chance encounter with the blue poppy in the wilds of Bhutan, suckered me into purchasing one at the RSBG's excellent plant shop. I know from cold, hard experience that the species blue poppy, Meconopsis betonicifolia, is difficult to keep alive. One of these poppies, the last plant I bought from the old Heronswood Nursery in Kingston, croaked the first year in the ground.
The cultivar Meconopsis 'Lingholm,' which I bought at RSBG, seems to be more forgiving. A peek beneath the mulch in my garden reveals evidence of life: an emerging rosette of hairy pale green leaves.
Late winter at RSBG this year, colonies of the evergreen perennial, Ypsilandra thibetica, were blooming. Their white spikes of fragrant bottle-brush blossoms lit up the wet pathways of the garden.
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