The Pacific Northwest Rhododendron Improvers

by Clive L. Justice

The rhododendron garden is of all the types of gardens uniquely English in its origin and development Its evolution begins in the late eighteenth century with what was at first termed the woodland or American garden. The former name was for the garden’s shady location in the English countryside woodlands while the latter was named for the origins of the plants used in the garden. Many of the early ornamental plants that came to England had originated in the great deciduous forest areas of Eastern North America with collectors like John Bartrum (1699 -1777), who sent seeds and plants to England collected from the English colonies of Virginia, the Carolinas and Georgia. The gardens’ connection to rhododendrons came about largely because a number of the American plants were ericaceous. Two of these ericaceous plants were the natives: Rhododendron maximum and R. catawbiense. Another ericaceous plant that passed for a rhododendron was Kalmia latifolia, along with several deciduous ericaceous plants, the American woodland azaleas. Thus the woodland/American garden became, over time, roughly from the late 1780s to the 1860s, identified as a Rhododendron garden.

Apart from those who grow and breed roses, some of the greatest ‘improvers’ of garden shrubs are those numbers of amateurs and professionals who tinker with this great genus of plants in the Heather family, the rhododendrons. This genus also includes the evergreen and deciduous azaleas. The Europeans, particularly the English, began in the middle of the 19th century and by the 1870s made rhododendrons the aristocrats of garden plants. The North Americans, Australians and New Zealanders didn't begin ‘improvements’ to rhododendrons & azaleas until the early to mid 20th century. In the Pacific Northwest and coastal British Columbia ‘improvements’ began only in the 1920s and ‘30s. However the great bulk of the work occurred in the 1950s and ‘60s, and continued into the next three succeeding decades. It will be shown that all these latter improvements relied almost exclusively on the hybrids developed in English gardens and nurseries and the ‘parents’, species that came via England from India, Nepal, Sikkim, China, Japan and North America.

One of the first in North America and the very first in British Columbian to hybridize rhododendrons was George Fraser, nurseryman of Ucluelet on the westcoast of Vancouver Island. In 1918 or thereabouts he crossed the native species Rhododendron macrophyllum, then known as R. californicum, with a hybrid he had purchased from Layritz Nurseries in Victoria, R. ‘Prince Camille de Rhoan and the species R. arboreum. He also crossed the Oregon/California native, the Western azalea, R. occidentale with the Eastern US azalea R. arborescens and a japanese azalea R. japonicum with a Nova Scotia azalea R. atlanticum. The last mentioned cross produced Fraser’s azalea (Figure 1a) while the former two crosses may have produced progeny. Fraser only mentions that he made the two crosses in his talk to the Twenty ninth Annual Convention of the Pacific Coast Association of Nurserymen meeting in Portland in October, 1929.

One of the many broad leaved evergreen rhododendron species that played a role in the Pacific Northwest hybridizing is the eastern Himalayan species, Rhododendron griffithianum . It was discovered in 1848 by Joseph Hooker and named for William Griffith, a friend and superintendent of the Calcutta Botanical gardens. Rhododendron. griffithianum became the basis for a group of magnificent flowered white to pink fragrant flowered rhododendron hybrids developed in England by Lord Edmund Loder. Called the Loderi group or grex, there were names for individual selections: ‘Loderi Venus’ (pink), ‘Loder’s White’, ‘Loderi King George’ (flesh pink), ‘Alpine Glow’ (pale pink) and ‘Beauty of Littleworth’ (white with purple blotch). This last name was the title of the estate next door to Lord Loder's Leonardslee in Horsham, Surrey.

These rhododendrons rapidly grow to 15 to 20 ft., and have nine to twelve inch high trusses of four inch diameter flowers. They soon set the style and standard for the late Victorian and Edwardian large suburban gardens in Surrey, Hampshire, Devon, Somerset and Cornwall. These magnificent plants were perceived to be too difficult, too tender and too large and leggy for any garden but the largest estate least of all the smaller Pacific Northwest suburban garden. However, they were used extensively for hybridizing in the Pacific Northwest to produce plants more suited to our local climate and gardens. The University of Washington Arboretum in Seattle, an Olmstedian landscape, has a fine collection of these ‘Loderis’. The arboretum was planted in the 1950's during the early part of Brian Mulligan’s term, (1946 -1972) as curator. Some of these ‘Loderis’ are now over twenty feet in height and spread, 40 years after their introduction.

Rhododendron griffithianum is perhaps the most important species to Pacific Northwest and BC coastal gardens of the 26 Sikkim rhododendrons that Sir Joseph Hooker collected. It was from the ‘Loderis’ and the many English hybrids that have the genes of Griffith’s rhododendron, that the gene pool originated for the Pacific Northwest's large leaved, large flowered hybrid rhododendrons that are now available for coastal gardens. One Pacific northwest example is the ‘Walloper’ Group or grex of hybrids, of which the cultivar ‘Point Defiance’ is one. It was named for a large park in Tacoma and made by Alaska fisherman turned hybridizer, Hafdan Lem. It has over 50% griffithianum genes through its complex development from English hybrids ‘Beauty of Littleworth’ to ‘Norman Gill’ and ‘Jean Marie de Montague’ to ‘Anna’ to ‘Marinus Koster’. All of these great hybrids that still find a place in many coastal gardens have R. griffithianum as a parent. It would be well into the 1970's before any of these home grown rhododendron hybrids became common garden plants in coastal gardens. Many still are only grown in the gardens of rhododendron collectors, hobbyists and enthusiasts.

A rhododendron species that is of equal or even of more importance in producing hybrids suitable for the Pacific northwest and BC coastal gardens is the sun loving, small, heart shaped leaved species Rhododendron williamsianum. It was discovered in western China by Ernest H. Wilson, the plant explorer and introduced as a garden plant in 1908 via the Veitch Nursery in England. Rhododendron williamsianum is a species that needed no improvements to make a fine garden plant but in the Pacific Northwest those raised from seed that was sent free by the Royal Horticultural Society to its members and from other seed sources in the United Kingdom became plants grown only in collectors and rhododendron enthusiasts’ gardens. It is quite unlike the traditional rhododendron both in flower and foliage, and while it prefers well drained acidic soils like the more traditional larger leaved rhododendron hybrid it differs in a preference for garden situations in full sun in Pacific westcoast gardens. 

The most widely known Rhododendron williamsianum improvement for beauty of flower and foliage is ‘Bow Bells’. It was hybridized in England in 1933 but was not used in Pacific Northwest gardens and landscaping until some twenty years later. A low growing mound reaching three to four feet in height with an equal spread, `Bow Bells' likes full sun situations in Vancouver and Vancouver Island gardens while dappled shade suits it best for gardens in Portland and south. Harold Greer describes `Bow Bells' qualities best:

 “. . . In blossom `Bow Bells' is a perfect mound of luscious pink flowers appearing first as deep pink buds, contrasting with the opened flowers giving a two toned effect. The flowers are followed by shiny copper, new leaves appearing at every stem tip. A display by itself. The season changes, and day by day the mound becomes a superb jade green with rose red bud scales.”

The two species Hooker’s R. campylocarpum and Wilson's R. williamsianum were crossed to produce `Moonstone' in England in 1933. It produced a comely shrub that grows to five feet. It is a compact grower with shiny green heart shaped leaves and light yellow bell shaped flowers. A rhododendron with a similar meeting of the two species through the Loder route and bred in the Pacific Northwest by Roy Clark of Olympia Washington is ‘Olympic Lady’. It is taller growing with larger leaves than ‘Moonstone’ and the flowers, more campylocarpum like, are pink fading white [there is a pure white flowered form], larger than ‘Moonstone’s’ light yellow bells. ‘Olympic Lady’, pink or white form and ‘Moonstone’ have been used together effectively in the smaller Pacific Northwest gardens. In full sun both are compact while in shade both grow loose and lanky. In the cool coastal Pacific Northwest the williamsianum hybrids are some of the very best small garden plants; their early bloom coincides with April, the month of finest spring display, with flowers and foliage in keeping with the floriferousness, fine detail and texture that the smaller garden with fewer plants needs. 

Ordinary gardens established in the 1930s and ‘40s in Vancouver and environs and in Vancouver Island communities did include the traditional Victorian rhododendron hybrids as lawn specimens. Many of these were varieties in a class of English rhododendrons labelled ‘Ironclads’ for their supposed cold hardiness and thus suitablity for the US eastern Atlantic coast market, Long Island, Cape Cod and Boston These had become available to Pacific Northwest and BC coastal gardens through local nurseries as early as 1910, but most probably came in the late 1920s and ‘30s. These were rhododendron hybrids with names like ‘Cynthia’, a cherry pink, ‘Fatusosum Flora Pleno’, a semi double mauve, ‘Roseum’ and ‘Roseum Elegans’, both rose, ‘Boule de Neige’ a white and the dark red ‘Nova Zembla’.

In a few instances these rhododendron hybrids have survived into the post Second World War decades. Some, in woodland settings have grown into small trees or very large shrubs in abandoned and neglected gardens in the milder and wetter areas of the west coast of Vancouver Island, the Queen Charlotte Islands, Prince Rupert and in well cared for gardens in Vancouver and New Westminster, where the front lawn in which the latter are situated receives occasional summer watering. As most of these old hybrids were grafted onto the more vigorous roots of R. ponticum seedlings or the R. caucasicum hybrid ‘Cunningham’s White’, these have sometimes taken over the named hybrid so that the understock, the more vigorous mauve flowered ponticum and the white-yellow centered Cunningham’s White’ replaces them.

A northwest native rhododendron that is a beautiful deciduous shrub, is the western Azalea, or R. occidentale. In the past this fine flowering plant has played a large and significant role in England in the breeding and development of the big, intensely coloured, orange, peach, pink, red and yellow hybrid deciduous shrubs for the garden. First out were the Knaphill Azaleas. In 1870 Anthony Waterer of Knap Hill Nursery at Knaphill, Woking, UK began hybridizing using the species and developed hybrids of the deciduous rhododendrons that included those hybrids from Belgium and species from eastern North America, China, Asia Minor along with R. occidentale from western North America. Then in the 1920's these Knaphill’s were hybridized further by Lionel Rothschild of Exbury Gardens in Hampshire to produce the Exbury strain of azaleas with flowers that are bigger, more intense with a wider range of reds, oranges, salmons, apricots, yellows, pinks, whites and combinations of these colours. Exbury Azaleas came under such names as ‘Oxydol’ -( whitest white), ‘Honeysuckle’ - (flesh pink with orange flare), ‘George Reynolds’ -(brilliant buttery yellow), ‘Klondyke’ - ( glowing gold), ‘Clarice’ - (pale salmon with orange patch), ‘Hotspur Orange’ - (orange red), ‘Scarlet Pimpernel’ - (obviously red), and ‘Gibraltar’- (a spectacular orange red). There were, and are still, many more names of these big flowered, many coloured, strong growing hybrids grouped under the names of the English nurseries that produced them, Slocock, Windsor, Knaphill and Exbury. These azaleas were not released for garden use in England until about 1924, and did not reach the Pacific Northwest until the late 1940's.

In the Pacific Northwest, the Bovee’s Nursery of Portland and amateur enthusiasts Arthur Wright, Howard Slonecker, the late Eric Langton of Maple Ridge in the Fraser Valley and Jock Brydon of Eugene, Oregon carried on improving the flower size and colours of this complex group of deciduous shrubs. Locally, selections of the deciduous azaleas are grown from seed and those with improvements to flower size and colour are raised by cuttings for the market. In the Pacific Northwest these azaleas have been selected and bred almost exclusively by amateur rhododendron enthusiasts, and they give an even wider range of colours to grow in Pacific coast gardens. The seedlings raised from the native species, itself a fine garden plant, are also a part of this rich feast of available colour and variety. Pacific Northwest selection and introduction of the native forms, variations and hybrids of the Pacific Northwest azalea, R. occidentale has been going on for less than a generation .

Because these azaleas lose their leaves annually, they go out in a burst of colour to provide a second season of display in autumn when the leaves turn red, yellow, gold & rust, sometimes equaling the flower display of spring. Stan Sorenson of Abbotsford has originated a deciduous azalea with huge yellow flowers he named ‘Cheerful Giant’ along with one with rosy pink blooms that have a red ‘eye’ that is aptly named ‘Stan's Tutti-Frutti’.

The grafting of newly created hybrid deciduous azaleas has left Pacific northwest and BC coastal gardens a small legacy of sorts from the gardens in the first decade of the last century. When the Knaphill, Ghent’s and Mollis azaleas were first introduced, all these new colour and named hybrids were grafted, like the evergreen rhododendron of the same era, on the understock roots of a species, that had originated in the Caucasus mountains between the Black and Caspian Seas. One that was most used was Rhododendron luteum and since this rhododendron’s roots stool (spread and grow suckers), the grafted hybrid can be overcome if the suckers are not removed. Many gardens found that instead of the vivid pink Mollis azalea, ‘John Ruskin’ for example, that had been originally planted there was instead a thicket of stems that appeared with fragrant golden yellow flowers. Vigorous and spreading, these ‘Luteums’, if found in an old garden, are a good tipoff that it was planted at an earlier time

The biggest, boldest, brightest and best of the Pacific Northwest rhododendron hybrids is ‘Anna Rose Whitney’. Named for the mother of the hybridizer W. E. (Bill) Whitney of Camas and Hood Canal Washington, it was introduced in 1954. ‘Anna Rose’ has a good measure of Hooker's R. griffithianum genes from one of the English parents ‘Countess of Derby’ to give it large stocky form, thick heavy foliage and large strong dark pink flowers. Its quality and character and vigorous growth make ‘Anna Rose Whitney’ a good dramatic specimen plant for the coastal garden. The late Bill Whitney scored with another great hybrid for the Pacific Northwest. This superb large foliage, large growing rhododendron he named ‘Virginia Richards’. With its parentage ‘Virginia Richards’' will certainly reach tree proportions in 20 to 30 years. This jewel of a plant was introduced into British Columbia coastal and Fraser Valley gardens by the late-jeweler-rhododendron collector and connoisseur, Ed Trayling of Surrey B.C.

 H. Larmar Larson of Tacoma hybridized rhododendrons with R. griffithianum genes to produce the red flowered hybrid he named ‘Malahat’. The name honours a Vancouver Island tribe of Pacific Northwest Indian peoples who have a mountain on lower Vancouver Island named for them. A fine yellow flowered rhododendron was developed by Dr. Bob Rhodes of Gabriola Island. He gave it a name that honours the Queen Charlotte Island's native people, the Haida. ‘Haida Gold’ has some of the genes of R. campylocarpum through ‘Goldsworth Yellow’ an English hybrid and R. wardii, species collected by and named for the, plant explorer Frank Kingdon-Ward.

 A newly registered yellow on the Pacific Northwest Canadian scene is the complex hybrid developed by Dr Margaret (Mike) Trembath of Surrey B.C., that she has named ‘Lionheart’. “[It] is a warm yellow with brick red buds, a frilled calyx and a bloom time of the first two weeks in June . . . a plant that smiles” is her apt description. Many people had a hand in producing ‘Lionheart’. First were the plant explorers in finding the species in Lionheart's makeup, Ernest Wilson, for Rhododendron souleii, George Forrest, for R. apodectum, and Kingdon Ward, for R. wardii along with hybridizers, Lionel de Rothchild for the hybrid ‘Rimini’ and Larmar Larson of Tacoma for the hybrid ‘Mrs. Lamont Copeland’. Crisp foliage, layered look, late flower with a compact low growing form makes ‘Lionheart’ “the bridge into summer.”

Another Pacific Northwest peachy yellow flowered rhododendron creation with a good stock of genes from Hooker's R. griffithianum that has proved to be an all-around great plant for the garden is ‘Butter Brickle’. Jack Lofthouse of Vancouver BC originated this floriferous, compact growing shrub that has flowers that appear double as the outer leaves or calyx forms an overskirt about the base of the individual flower.This apron has the same pink and yellow as the flower.  Most likely ‘Butter Brickle’ gets this unusual flower feature from the species R. dicroanthum. It was found in 1907 by the great collector of plants, particularly the genus rhododendron, George Forrest, who collected exclusively in Western China from 1904 -1931. George Forrest made seven expeditions there to collect seed of rhododendrons for the nurseries and private gardens who were his sponsors, over the period 1907 to 1932. Forrest found R. dicroanthum on the Tali (Dali) Range in western Yunnan Province. On a later expedition in 1917, he found R. griersonianum in the Shweli-Salwin Divide in West Yunnan Province. When raised in England R. griersonianum was too tender a plant for all but the mildest of English gardens, but to the hybridizer and nurseryman the pure red flower (it had no hint of blue pigment), provided the possibilities of hardy hybrids with pure red flowers.

One of the best is named ‘Elizabeth’ for Queen Mother Elizabeth and introduced to English gardens in 1939, just before the Second World War. ‘Elizabeth’ did not appear in British Columbia coastal gardens until 1954, when this fine textured low growing rhododendron was introduced by Len Living, a nurseryman and landscape contractor of Richmond B.C. ‘Elizabeth’ is both vigorous and floriferous, with pure red trumpet flowers that cover the plant in early May. 

The bicentennial of Captain Vancouver’s charting voyage to Pacific Northwest waters occurred in 1992. This year was also the centennial of the founding of Burnaby, the community that shares Burrard Peninsula with the Captain’s namesake city, Vancouver. To honour this occasion the Burnaby Beautification Commission held a competition to select a rhododendron hybrid that would be suitable for the parks and private suburban and urban gardens of Burnaby and to carry the name ‘Burnaby Centennial’. The rhododendron that won the name was hybridized by Ed Trayling, but grown on and introduced by Vern Finley a collector and amateur breeder of rhododendrons, in Surrey, British Columbia. ‘Burnaby Centennial’ is a mid May bloomer with a strong tight truss of large red flowers and good size leaves. It is a strong and vigorous grower and yes, it does have some genes from Hooker's collecting in Sikkim one hundred and fifty years ago. ‘Burnaby Centennial’ looks to be every bit as vigorous and accommodating to garden and park conditions as ‘Anna Rose Whitney’ has proven to be.

‘Burnaby Centennial’ also owes much of its deep red colour to the late blooming species R. griersonianum that was collected by George Forrest. It gets some of its R. griersonianum red through `Fusilier’ and its lime green slightly wavy leaves and tight classic truss of flowers from ‘Corona’ an old hybrid with Hooker’s R. griffithianum genes. Les Clay, nurseryman and tissue culture propagator of rhododendrons in Langley, B.C. has introduced ‘Eva Clay’, a R. yakusimanum cross with R.. smirnowii that has passed on the genes of compactness, leaf shape and silver leaf indumentum with a striated dark pink flower which suits the plant.

In 1967 to celebrate the centennial of Confederation and adoption of the rhododendron as Burnaby’s official flower the then District Municipality undertook to create a rhododendron garden on the ornamental treed grounds of an old estate that overlooked Deer Lake. The large mansion was converted to serve as a municipal art gallery. Landscape Architects Philip Tattersfield and Associates were commissioned to prepare a landscape layout of planting beds and walkways under the large existing trees on the east sloping grounds northwest of the new gallery. The shaded display beds were to be stocked with as many rhododendron hybrid varieties as could be obtained locally from commercial nurseries. Each display bed was initially planted with rhododendron hybrids whose flowers were the same or near the same colour, e.g. all scarlets together, dark pinks, mauves and so on for each colour, in separate display beds.

The value of of this collection from a rhododendron heritage perspective is that it shows what rhododendron hybrids were available in the decade of the 1960s and that most were English hybrids. Some 80% were of English origin, 5% from Eastern US and 15% were hybridized in the US Pacific northwest. If one were to have planted the same type of display two decades later, the hybrids of English origin would have only dropped to 60 %, the eastern US would have remained at 5% and the US Pacific Northwest (PNW) hybrids would have risen to 35%. Of this latter 1 to 2% would have been from B.C. While these are rough approximate percentages they do indicate that there are many English hybrid rhododendrons, some more than 150 years since they were created, that are still superior in many ways to the newer North American hybrids and so continue to be grown in coastal gardens.

The Canadian component of the PNW hybridizing was augmented in 1984, when the the late Milton Wildfong, rhododendron grower, hybridizer and nurseryman of Mission in the upper end of B.C.'s Lower Fraser Valley, developed and registered a complex hybrid rhododendron he developed and named ‘Ruffles and Frills’. This fragrant frilled floret, yellow on the inside, pink on the outside, twelve in a flower truss, ties together in it’s makeup the three eras of rhododendron development. The heritage of ‘Ruffles and Frills’ it’s fragrance, frills and foliage, includes the late Victorian - Edwardian, R. griffithianum, the Georgian 1920s and ‘30s with R. griersonianum, and the modern Elizabethan - Queen mother and Queen with R. yakusimanum. ‘Ruffles and Frills’ is a four to six foot plant with heavily textured leaves that last for three years and are bronzy when young. It is not unique in this heritage as there are many new rhododendron hybrids that have this century and a half linkage with the species from the slopes of the Sikkim, Himalayas, the Gorges of China's rivers and the islands of Japan. The complexity of parentage makes for beautiful and adaptable garden plants. Although our coastal gardens are invariably spring gardens, these complex hybrids will perform in all seasons of today’s small coastal suburban/urban garden. 

Clive L. Justice