QBARS - v16n4 Rhododendrons in the USA & Canada

Rhododendrons In The USA and Canada
Dietrich Hobbie, Linswege, Germany
Translated from the German by Alfred Huber

The Rockery Section, Test Garden at Crystal Springs
Fig. 33.  The Rockery Section, Test Garden at Crystal Springs
Hobbie photo

The International Rhododendron Conference from May 10 to 14, 1961, at Portland, Oregon, afforded me the opportunity to get acquainted with my rhododendron friends in the United States and in Canada, and see with my own eyes the results of their breeding, about which we have often read in letters to each other.
An invitation from Mr. P. H. Brydon, Director of the Strybing Arboretum Society of the Golden Gate Park, San Francisco, caused me to make my trip directly from Frankfurt to the wonderful city on the Golden Gate by air. The Boeing jet 707 had the longest day of my life in store for me! This unforgettable trip by air with between stops in Paris and Montreal, started at 10:30 o'clock a.m. By 7:15 o'clock p.m., with the sun still high above the horizon, the machine made a big turn over Golden Gate and came in for the landing. It seemed the city was standing on a tilted plain hanging in the sky, a breathtaking as well as amazing picture.
In San Francisco, after a short custom inspection, I was met by a relative who lives in Oakland and who immediately brought me to his home in the car. In the gardens the roses were in bloom, and I saw my first rhododendrons, camellias, and palms the same evening. The wind was blowing cool from the Pacific in the evening, strange bird calls in the bushes could be heard. It was difficult to get accustomed to the new surroundings so fast.
At the office of the Golden Gate Park we all met for the first time and got acquainted with each other: rhododendron friends from all over the world, from Canada, New Zealand, Scotland, England and, of course, from the United States. The beautiful park, bordering on the upper end on the Pacific, has a world-renowned selection of rhododendrons. Although the annual precipitation is only about 15 inches, all rhododendrons made a very good impression. The key to the solution: Mulching with a 5 to 8 inch deep layer of chipped brush and sawdust. With proper fertilizing and irrigation the rhododendrons and azaleas respond splendidly, even if the ground is rocky and contains very little humus. On the whole length of the Pacific coast to Vancouver, British Columbia, I had seen this practice applied, partly with sawdust or with redwood bark (sequoia sempervirens) which had a wool-like appearance. By every tree nursery or larger rhododendron plantings there were heaps of sawdust. (The sawmills process mainly Douglas firs, sequoias, and ponderosa pines.) The sawdust is used as it comes from the mills. Probably our peat moss is more suitable for this purpose, but in the absence of the latter, wood wastes can be used successfully.
The Golden Gate Park has a collection of 300 different species of rhododendrons and many hybrids. Our small group wandered on May 4, through the magnificent setting, partly on shaded and partly on sunny paths. Beautiful R. nuttallii with fragrant, lily-like blossoms were in full bloom. Many rhododendron species of the hardiness C-D-E were doing well in the sunny, dry but relatively moist air of the coastal climate of California. Never in my life have I seen such pretty and luxuriant Rh. 'Pink Pearl' as are in the Golden Gate Park, and later iii the gardens of Eureka in northern California. Apparently they had formed roots above the graft in the decaying mulch; this would indicate that this large blooming R. griffithianum x fortunei could be tolerable of lime with its own rootstock. R. griersonianum hybrids are, so it seems, quite the vogue in western America. I have seen them in countless gardens all along the way to Vancouver, Canada.
An especially delightful experience was a visit to the Botanical Gardens of the University of California at Berkeley. Ignoring the warning at the main entrance, that occasionally rattle snakes find their way from the near hills into the Gardens, many of the rhododendron lovers set out to see the truly rich treasure of plants, seemingly in contrast with each other, in this world famous garden. Many high cacti and countless species of this desert plant grow only a few hundred yards away from the rhododendron paradise along a small brook in a ravine. Here, under the able care of Mr. Christ. grow the most beautiful rhododendrons. subtropical species, such as R. falconeri , R. nuttallii , griersonianum beside the winter-hardy rhododendrons of the catawbiense series, also the treelike R. sinogrande , R. thomsonii and R. decorum . How wonderful was the whirring of the humming birds amid this grandiose display of colors. It is astonishing to see the adaptability of the rhododendrons, even such species as are accustomed to colder temperatures.
After a 9-hour bus trip from San Francisco I arrived in Eureka, a stopover on my way to Eugene, Oregon. I will never forget this trip over the famous Redwood Highway 101. Partly running along the rocky coastal strip and the seething Pacific the highway led through dim redwood groves, the majestic Sequoia forests, incomparable with anything in the world. It was seldom that I could not see R. californicum in the glens.
In the evening hours of May 7, I took a walk through the streets of this broad scale planned city in northern California, and I was surprised to see such healthy and beautiful rhododendrons. In many front yards and against the walls of the neat, mostly wooden one-story houses the R. 'Pink Pearl' were in full bloom. Here, too, the ground was covered with mulch of redwood bark or sawdust.
In Eugene, a busy city in Oregon, I again contacted rhododendron people who overwhelmed me with invitations. There are numerous rhododendron lovers and growers in the vicinity of Eugene. Rhododendrons in this far more rainy and cooler region of the Pacific coast are often grown in small stands (groves) of Douglas firs, cedars, and hemlock trees.
On the beautiful McKenzie river, bedded in at the edge of grandiose Douglas fir forests, we probably saw the prettiest privately owned rhododendron park on the West Coast of America. It was developed and is owned by Dr. Phetteplace. Some rhododendron friends from England used the opportunity to go rainbow trout fishing in the McKenzie river. Here in the mild, rainy climate of Oregon were the most beautiful rhododendrons of all; deep blue R. augustinii , R. 'Hotspur', a red Exbury azalea attracted everybody's eyes. R. griersonianum and R. griffithianum hybrids were in full bloom. The edge of the whole woods were adorned with unlikely large dogwood blossoms. Especially well did I like R. 'Hawk Crest,' a deep yellow hybrid.
We wished we could have stayed longer at this blessed spot full of blossoms, mighty trees and roaring water. Dr. Walker's park, right close by, and with like conditions, presented a picture of propagating activity. Numerous fans, gardeners and especially the women were active with the hybridization of rhododendrons. The American Rhododendron Society promotes all phases which have to do with the culture and growing in a splendid manner. The different chapters of the American Rhododendron Society arrange shows and meetings. I was very much pleased with this cooperation, especially about the very active part the women take in it.
The climate on the west coast up to British Columbia is mild, and especially Oregon, Washington and the Frazer delta have much rain. The air currents from the Pacific unload their moist contents, which they absorb from the warm Japanese current, first along the coast, and then further inland, 80 to 100 miles from the coast in the Cascade mountains. On the western slopes of these mountains the clouds come down as rain and produce the lush vegetation, which has become known the world over for its immense wealth of conifers. In these forests grow R. macrophyllum and R. occidentale together with gaultheria shallon , preferably in pine forests. The whole coastal strip offers good growing possibilities, due to the mild climate and high moisture content of the air. Therefore the rhododendrons are strongly represented in the gardens. R. griersonianum hybrids and camellias are growing as far as Vancouver, B.C. Of course, one does take the chance that they will freeze back at intervals of several years, because occasionally there are cold winds moving in from the Rocky Mountains and Alaska.
The real Rhododendron Conference was held in Portland from May 11-14. The large number of participants stayed at the Multnomah Hotel, where also the conferences and the lectures took place. Many interesting colored pictures of the activities of whole groups of gardeners and their latest efforts in rhododendron culture were shown.
Director Brydon of the Strybing Arboretum in San Francisco brought praise about rhododendrons on the Pacific coast.
Dr. Fletcher of the Royal Botanical Garden in Edinburgh, showed the marvelous treasures of that world famous rhododendron paradise.
Dr. F. P. Knight, Director of the R. H. S. Gardens in Wisley, brought pictures of the extended test activities in his homeland.
Dr. J. Wister gave a talk about the R. Dexter hybrids.
Dr. Gould gave a report about diseases of rhododendrons in western America. Of great interest was the lecture and the pictures by Sir Giles Loder, Leonardslee, about growing of the well known R. Loderi hybrids.
Mr. Grootendorf of Boskoop showed the latest rhododendron hybrids in Holland.
Mr. Leach of Brookville, Pennsylvania, one of the most experienced growers in the U.S.A., gave reports about breeding of winter hardy rhododendrons. This was followed by lectures about mulches for rhododendrons and azaleas.
American growers of importance, like Mr. Gable, Mr. Rudolph Henny, Dr. Clement Bowers, Mr. Shammarello and Mr. Larson showed the results of their work with rhododendrons and azaleas for many years.
A highly interesting report about rhododendrons in New Zealand was given by Dr. Yeates from the Massey Agricultural College in Palmerston, New Zealand.
Finally my own color pictures of the rhododendrons in Germany aroused lively interest in Portland as well as in Berkeley, Eugene, Vancouver earlier, and later in New York.

Test Garden at Crystal Springs
Fig. 34.  Test Garden at Crystal Springs, Portland, Oregon
Hobbie photo

H. L. Larson, Mr. Trayling and Mr. Living in Test Garden
Fig. 35.  Visitors at the Test Garden during the Conference,
H. L. Larson, Mr. Trayling and Mr. Living
Hobbie photo

Several groups made excursions into the vicinity of this beautiful city on the banks of the Willamette river. The Test Garden of the Rhododendron Society, Portland Chapter, afforded together with the rhododendron blossom tour on May 4, a magnificent picture in color at the peak of the blossoming time. This beautiful park is situated on an island with high Douglas firs, cedars and hemlocks, called Crystal Springs. Countless species of rhododendrons have found a home here, and one could be envious of the multitude of the tender species and hybrids, which were represented here in their full exotic beauty. The intoxication of colors and fragrance was everywhere.
In the Henny nurseries in Brooks, Oregon, the prettiest Exbury azaleas were just in bloom. Here, too, work is done to promote the development of this beautiful azalea, and of the rhododendrons in general. Many novelties emerge from these excellent nurseries.

A. C. U. Berry's Garden in Portland
Fig. 36.  Rhododendrons at A. C. U. Berry's home in Portland
Hobbie photo

Mrs. Berry's garden, not far from Portland, was developed into a spot of great beauty with rhododendrons among Douglas firs, cedars and dogwood trees. Invariably groups of trees on the edge of woods are selected for the planting of rhododendron gardens. Treelike dogwoods with blossoms brighten the place, where the dark trunks of the Douglas firs, cedars and hemlocks are predominant. The giant six foot in diameter stumps of the trees mentioned are in many places decaying, the last remains of a virgin forest.
I continued my trip together with Mr. and Mrs. Trayling to Washington and Vancouver, B.C. Everywhere in the gardens along highway 99 from Portland to Vancouver beckoned rhododendrons in full bloom. Near Tacoma we stopped for a visit of the Heinemann Rhododendron Nursery. This German immigrant has with tedious labor built up his culture on the rocky, loamy soil with good success. They grow rhododendrons, and Mr. Heinemann works especially with the further development of the Exbury azalea and griersonianum hybrids. The Heinemann family was very hospitable and served orange juice, a godsend during the prevailing heat.
The next stop was at Mr. H. L. Larson's place in Tacoma, where we stayed over night. Mr. Larson grows with great success rhododendrons on very rocky loam soil. In this open nursery I saw the giant-blooming hybrids with R. 'Pink Pearl', discolor , and griersonianum strain. The fondness and devotedness with which they took care of the rhododendrons, pleased me very much. The hospitality of the Larson family left a deep impression in my memory, and the trip along the Hood Canal on the east side of the Olympic peninsula offered fabulous natural scenic views. Everywhere along the coastal highway wild R. macrophyllum were blooming. From the massive Mt. Olympic came the glimmer of the snow: and swift salmon rivers, flowing toward the sea. To start a rhododendron nursery by a salmon river like this, and on the edge of a forest would be my goal if I were to leave my homeland.
In the center of the Olympic peninsula is the Olympic National Park with a spread of 1305 square miles. Its western slopes have an annual precipitation up to 110 inches and more (in Northwest Germany 21 inches). Nature has formed here one of the most luxuriant rain forests in the world! In the Hoh Valley stands the biggest Sitka spruce in the world with a circumference of 46½ feet 6 feet above the ground. Generally, the sitka spruce grows only in the coastal region, where there is a high precipitation of rain. The biggest hemlock ( Tsuga heterophylla ) stands also in the western part of the Mt. Olympic range, on the upper Quinalt river. Its circumference is 28 feet. On the Queets river one can see the biggest Douglas fir in the world with a circumference of 52 feet 5 feet above the ground. All over one can see giant cedar trees ( Thuja plicata ). The biggest tree of this kind is at the Ruby Beach near the coast in dense, moss-covered forest, where it was discovered only in 1954. It has the unbelievable circumference of 60 feet 5 feet above the ground! Abies grandis , a large fir, grows in this rain forest to gigantic size. In higher regions in an altitude of 4600 feet, one finds only the slow g rowing mountain conifers. Especially enchanting, sometimes covered with hoarfrost of a bluish hue, were the mountain hemlocks, which grow there mostly among the overly slender, spear-like Abies lasiocarpa .
Here stands Mt. Olympic, massive with its glaciers that nourish steady flowing streams into the valley to the Pacific and to the Straits of San Juan de Fuca in the north. On the driftwood covered coast wait the salmon for the right time to reenter the stream of their birthplace.
After the visit of Hurricane Ridge on massive snow-covered Mt. Olympic, we took the ferry boat to Seattle. Seattle has a magnificent arboretum with a remarkable rhododendron section. Species of R. sutchuenense , augustinii , thomsonii , wardii , puralbum , 'Loderi', 'Azor', griersonianum hybrids, fargesii , orbiculare , houlstonii , catawbiense hybrids stood along side countless other rhododendrons in bloom, some already with new shoots. Here, too, the growth on the rocky loam soil has been supported with sawdust.
The days from May 18 to 24 in Vancouver became an unforgettable event. My rhododendron friends, the Traylings took me into their home and during my stay showed me everything that had to do with rhododendrons. There are many persons interested in rhododendron in Vancouver. They all have in this incomparably beautiful country a very favorable climate. Everywhere are small nurseries, where they work intensively with rhododendrons and evergreens. The hobbyists sometimes experiment with the hybridization of rhododendrons in their small green houses.
I was surprised to see in Mr. Trayling's garden my R. repens and R. williamsianum , which were exported by a firm in Boskop. Mr. Living's nursery in the Frazer delta and the nursery of Mr. Eddie & Sons are important in the growing of rhododendrons. The Botanical Garden of the University of British Columbia has an extensive collection of rhododendron species. R. telopeum , calophytum , 'Mars' and many species of F. K. Ward, and Camellia 'J. C. Williams' are sufficiently hardy in the same latitude as Frankfurt.
Vancouver, situated in the Frazer Delta, has a truly extensive park system on several elevations in the delta. Widely known is the Queen Elizabeth Park and the Stanley Park. The latter has for example an area of 2896 acres. All parks have abundant plantings of rhododendrons. One can find there the newest hybrids and the newly introduced species as well as all the better known rhododendrons. Mr. Livingston, the director of the gardens at Vancouver, really has achieved exemplary accomplishments.
In the background, north of Vancouver, gleam the snow fields of the Garibaldi Provincial Park and of the Mt. Seymour Provincial Park. There the realm of the rhododendron ends, and the Canadian wilderness starts.
The east coast of North America has an altogether different climate. A gardener told me that in the hinterland of Boston they have the summer of Rome and the winter of Moscow.
When I arrived in New York on a Canadian train, I could still see traces in the gardens of the severest winter in 40 years in New Jersey and on Long Island. Branches of R. catawbiense which were exposed to the winter sun, looked quite brown. In the nursery of Paul Vossberg, Long Island, I saw the result of the winter on rhododendron test plants in an open space. Almost all the plants were more or less frostbitten. Here I could clearly see how important the breeding of the most winter hardy rhododendrons for such regions is. Valuable work has been done in America in the last decades by growers such as Mr. Dexter, Mr. Joseph B. Gable, Mr. Nearing and Mr. Shammarello. In the latter years, the breeding of the winter hardy rhododendrons has especially been advanced by Mr. D. G. Leach, Brookville, Pennsylvania. I found that the following hybrids withstood the winter especially well: R. 'Boule de Neige', 'Dexter's Sensation', 'Louise Gable', 'Roselyn', 'A. Bedford', 'Purpureum Grandiflorum' and 'Dexter's Parkers Pink,.
There are wonderful parks on Long Island with numerous rhododendrons. I spent a beautiful afternoon visiting these gardens. In the park of a millionaire, the 80-year-old owner was still busy among his rhododendrons with hybridizing. Here rhododendrons of the more tender species were blooming, such as R. 'Vulcan' and others like it in sheltered places. This proves how conifers can give winter protection.
Japanese azaleas in the raw eastern climate are quite hardy. In many front yards I could see high specimens. The good seasoning of the wood in the warm summer is advantageous for the wintering. In Wayne, New Jersey, are the Laurelwood Gardens. The owners, Mr. and Mrs. Knippenberg, have built up a wonderful rhododendron park in hilly woods between dogwood trees, maples, pines and oaks. Countless rocks and smaller granite stones were excavated. The ice age glaciers had broken them from the Canadian shield and moved them far to the South. Colonies of very pretty lady slippers ( Cypripedium acaulis ) in rose and yellow hues were blooming under the trees. It took several hours to walk through all the gardens. led by the enthusiastic Knippenbergs.
Everywhere in New Jersey, Pennsylvania, Connecticut and Long Island they are interested in the rhododendrons and in hybridizing. I saw the gardens of Mr. Burns and Mr. Casadevall and admired their fervor and love, with which they occupy themselves in their leisure time with garden work and especially again and again with rhododendrons.
All in all the trip through North America has given me the impression that the whole garden culture is influenced by rhododendrons today. Everywhere, even on places with an adverse climate, they try - and almost everywhere with good success - to cultivate this lovely plant. The reason for this accent lies in the discovery of the many species, which came to us only in the last 40 years. Coming originally from different climates of the world and different soils, these species inherited through skilful crossing with suitable partners all the characteristics which enable the new hybrids to fare good under less favorable conditions. By comparing breeding results in Germany, especially my own, I could confirm that we are on the right track.