The Pacific Northwest is natural rhododendron country. In that narrow belt along the Pacific slope running from Vancouver and Victoria, BC, to San Francisco, the winters are tempered by warm waters, the air is moist the year round, there is very little extreme summer heat and the soil is naturally acid. All this adds up to a perfect rhododendron formula. In this section, too, the soil texture is-mostly light, running from peat to good sandy loam; heavy clay loam is found only occasionally.
Gardeners who live within hailing distance of the waters of Puget Sound. which includes many islands, can grow the full range of British hybrids as well as the majority of rhododendron species from all parts of the world. Those who reside at a distance from the immediate influence of the warm currents, naturally, have to be a little more careful about their selections. But there is a wealth of fine varieties they can grow.
Three species of rhododendrons are native to the Pacific Northwest. R. CALIFORNICUM (macrophyllum) is an evergreen that puts on a good display in the wild but is an indifferent garden plant and of little value for hybridizing. R. ALRIFLORUM is an interesting deciduous sort that grows in the high Cascades and other mountain ranges of the area. Both of these are scattered over a wide area up and down the coast.
R. OCCIDENTALE, a very fine species of the azalea series, grows in Oregon and California. This species has been used to improve deciduous azaleas to a great degree. A natural hybrid between R. californicum and R. occidentale has proved to be a fine “”azaleadendron.””
England, of course, was the source of many of the fine hybrids. The British have many more years of experience in hybridizing and also have flowering size plants of all known species from which they can select parents. However, a great deal of intelligent effort is being expended in the Pacific Northwest to overcome this English advantage. More and more fine species appear in Northwest gardens every year and these are important to a hybridizing program. Much importing from England is being done, both species and hybrids, and many fine British forms are now big enough that nurserymen are propagating for commercial distribution.
Across the Sound on Bainbridge Island, Herbert Ihrig was a pioneer in collecting top grade rhododendrons. His interest is in such important and diversified species as R. THOMSONI. which takes years to produce its intense red bells; R. YUNNANENSE, with its sprawling, vinelikc branches and soft mauve flowers; and R. MOUPINENSE, a compact mound with large white flowers appearing in early winter.
Both hybrids and species are featured in gardens in Seattle.
A huge plant of R CAMPYLOCARPUNI won the sweepstakes at the Seattle Flower Festival Show in 1951. This plant had thousands of lovely yellow bells which almost covered it.
At the University of Washington Arboretum at Seattle, there was a wealth of hardy rhododendrons. A big plant of R. SUTCHUENENSE which is sheltered from March frosts causes visitors to marvel at its bountiful supply of orchid pink flowers in early spring. In May, drifts of R. AUGUSTINI, ranging from sky blue to deep purplish blue, are startling. At this time of year the area known as the Rhododendron Glenn is bright with hundreds of varieties in full flower.
The late James E. Barto of Junction City, Oregon, was one of America’s greatest authorities on rhododendrons. His collection was extensive and included hundreds of species. He also made many crosses, some of which preceded the same crosses to be made in England. Mr. Barto’s crosses still hold their own with the best of the new ones. Mrs. Horace Fogg of Tacoma named one of these RENAISSANCE RED. It is a cross of Peter Koster and IL loderi variety King George. Its color is unique among rhododendrons.
H. L. Larson pioneered in growing rhododendrons in Tacoma, Washington. Years ago he collected species seeds from a number of sources including the old British Rhododendron Society, a collector in Darjeeling, India, and the Lu-Fham Arboretum at Han-Po-Fu, China. Many very fine varieties of species which are now of flowering size resulted from this project.
Azaleas also hold a prominent place in the garden. One particular planting of evergreens is a fine demonstration of what can be done with mass grouping of azaleas. It includes R. MACRONATUM, pink MmoNMAYO and orchid ATLANTA, blending their colors with many others to form a veritable Persian carpet. Orange, red and yellow deciduous azaleas also produce a riot of color at the Coen place every spring. A very fine plant of the exotic LADY CHAMBERLAIN, Exhury variety, is Mrs. Coen’s pride and joy. The pink trumpets that cover this one charm all beholders.
