QBARS - v4n1 Rhododendrons and Azaleas at the Knap Hill Nursery

Rhododendrons and Azaleas at the Knap Hill Nursery
G. Donald Waterer, Secretary, Knap Hill Nursery Ltd

Hybrids at Knapp Hill Nursery
Fig. 4. Hybrid rhododendrons at Knap Hill
Photo Country Life, London

Historical Survey

During the eighteenth century the village of Horsell in the northwest corner of the county of Surrey consisted of a few houses with an ancient church set upon a hill. Two miles away low hills were outlined which marked the fringe of a large and desolate area covered with heather, pine trees, birch and oak. This was the notorious Bagshot Heath, a favorite haunt of highwaymen who lay in wait for coaches traveling from London to the west of England. Where the fields of Horsell merged into the heath land lay the small hamlet of Knap Hill, a collection of widely scattered farms which had sprung up during the sixteenth century. A small stream trickled from the heath and at the foot of the hill spread into a wide peaty bog the soil of which, being rich and black, greatly resembled the rhododendron soil of North Carolina.
We know that in 1724 Thomas Waterer was farming at Knap Hill, but we believe that it was his grandson Michael Waterer Senior (1715- 1827) who acquired the bog about the year 1770 and set to work to drain it, having realized its great advantage for the raising of rhododendrons, azaleas and other Ericaceous plants. His property included several of the adjoining fields where the soil, a deep sandy loam, was soon to harbor a great variety of trees and shrubs. Some of these are still standing, the most notable being a Weeping Beech which covers an area of a quarter of an acre.
Hybrids of Rhododendron ponticum and R. maximum were raised in the early 1800's and the introduction of R. catawbiense in 1809 by John Fraser marked the beginning of the development of the "hardy hybrids" which have ever since been associated with the name of Knap Hill. One of the original plants of R. catawbiense still exists in what was once the peat bog and although the main branches are hoary and decrepit, young shoots are still springing vigorously from the base of the stem. Azalea hybrids were also raised in those early days from A. pontica and from the azalea species which had been introduced to this country from America.
On the death of the elder Michael in 1827, the Nursery passed to his eldest son Michael Waterer Junior (1770-1832), a man of abounding energy and high spirits who until that time had spent several years away from Knap Hill. Thanks to his enthusiasm for the work of hybridization the Nursery made great progress during the 1830's. In May and June the display of flower was already imposing enough to attract hundreds of visitors and the latest hybrids were regularly exhibited at a show room in Regent Street, London.
When the younger Michael died in 1842, he left Knap Hill Nursery to his youngest brother Hosea Waterer (1793-1853) and a nursery which he had acquired at Bagshot a few miles away passed to another brother, John Waterer Senior (1783-1868), who was also a successful breeder of rhododendrons.
During the 1840's Hosea held an annual show in a great marquee in the King's Road, Chelsea. The newly opened South-Western Railway enabled him to send to London many hundreds of enormous rhododendrons and azaleas which were timed to open their flowers under canvas. Horse drawn carts were also used for transport and continued to he used for more than half a century. They were of a peculiar design and were always noted with interest in the villages through which these unusual convoys had to pass on their twenty-five mile journeys. The show became an event of the London season and did much to publicize the name of Knap Hill.
With the death of Hosea in 1853, the "early development" phase of the Nursery's history came to an end. He was succeeded by his nephew, Anthony Waterer Senior (1822-1896) and Robert Godfrey, who remained in partnership until 1868 when Anthony became the sole proprietor. A period of remarkable achievements began. Anthony was a man of firm character and opinions, the sort of man who is liked either very much or not at all. His brusque ways and rough speech were mollified by a great sense of humor which endeared him to a wide circle of friends from many countries. In 1860 a severe frost occurred which destroyed thousands of seedling Araucaria imbricaria in the Nursery. Thereafter he would not tolerate any plant unable to stand the climate of Knap Hill without protection. It became his aim to produce azaleas and rhododendrons which would flower in late May or early June when all danger from spring frost was over.
It was probably in the 1860's that Downing imported plants from Knap Hill for the Capitol grounds at Washington. An American publication has described how, after Downing's death, the unpaid bill for plants was found among his papers by his executor Henry Winthrop Sargent of Fishkill. Sargent was a school friend of Charles Sumner and with his help he succeeded in obtaining from Congress an appropriation to pay this bill. From this arose a lasting friendship between Anthony and H. W. Sargent. Many "ironclad" rhododendrons raised at Knap Hill were named after members of the Sargent family. In 1876 Anthony exhibited 1500 of his hybrids in Philadelphia, most of them being hardy enough to stand the climate of the Eastern States. He was well liked in America and it was a great pleasure to him to build up a considerable trade across the Atlantic.
The years 1870-1890 marked a period of intense activity in the Nursery. Not only rhododendrons and azaleas but also selected forms of Conifers, Laburnum, Cydonia, Spirea, Oak and a host of other plants appeared which even today, in many cases, stand unchallenged at the head of their class. Rhododendrons were displayed every spring during this period in Regent's Park, London, while a short distance away in Cadogan Place his rival and cousin John Waterer Junior conducted a similar display. Some confusion in between the two firms was inevitable, but the rivalry was recognized by both as healthy and stimulating.
Anthony Waterer Junior (1848-1921) inherited from his father nearly 300 acres of farm and nursery land. He carried on the work of breeding with marked success but, being a bachelor and a wealthy man, he did not part readily with the best of his plants. At times he was eccentric enough to order his foreman to burn a batch of his latest novelties. No one understood the reason for these sudden outbursts of waywardness. His men found him a tolerable though autocratic master. Several of them completed fifty years and more of service with the Nursery during his and his father's lifetime. The late Lionel de Rothschild was one of the few people to whom he would sell his best azaleas. Mr. Rothschild bred from them extensively at Exbury and their progeny are now officially known as the Exbury strain of Knap Hill azaleas.
When war broke out in 1914, Anthony took seriously to cattle farming and was forced to let most of the Nursery run wild until his men returned in 1919. When he died in 1924 his brother Hosea Waterer returned to Knap Hill from Philadelphia where he had founded a seed business. Although he and his family were American citizens he had a wish to end his days at Knap Hill. He died in 1927 and in 1930 the Nursery was bought by the present Company.
During the 1930's much was done to clear and clean the Nursery and to salvage the many treasures which it contained, but the renewal of war in 1939 once again caused the greater part of it to run wild. Since 1915, however, strenuous efforts have again been made. The production of rhododendrons and azaleas has made a particularly rapid recovery. Thousands of young plants backed by the magnificent specimens for which the Nursery has so long been famed are attracting visitors from far and wide.

Rhododendrons at Knap Hill

The oldest recorded hybrid rhododendrons raised at Knap Hill was R. 'Nobleanum' ( R. arboreum x R. caucasicum ) which was named in 1832 by the younger Michael, but we suspect that his father several years earlier had raised a hybrid of R. maximum and R. ponticum , which was later named 'Mrs. John Clutton' and awarded a First Class Certificate in 1865. It is interesting, and perhaps instructive, to record that this plant was admired by visitors to the 1949 Chelsea Show, not on account of its ancient history, but solely on account of its merits as a hardy hybrid rhododendron.
When the elder Anthony Waterer and Robert Godfrey took charge of the Nursery in 1853, there were several colour forms of the species R. catawbiense and R. ponticum , as well as a considerable number of hybrids between those two species and R. arboreum and R. caucasicum . For the next 40 years Anthony crossed and re-crossed his hybrids, raising every year many thousands of seedlings and selecting from them only those which showed a very definite advance on their predecessors. His criteria were briefly these. The hybrids must flower in late May or early June to avoid damage by spring frost. The truss must be broadly conical in shape and filled fully and compactly with flowers to withstand heavy rain. He did not admire self colors and preferred each flower to have a well marked blotch to give it form and substance. Foliage was also a prime consideration, for he liked his plants to be pleasing to the eye either in or out of flower.
Progress was soon made. In 1865 four hybrids received First Class Certificates. About this time the appearance of R.  'Doncaster ', perhaps the first really deep red hardy hybrid, must have caused considerable astonishment in the Nursery. In 1877 a visitor commented on the many rows of R. 'Album Elegans' grown as standards. The original plant of 'Mrs. John Clutton' was fifteen feet high and nearly as much in diameter, and the quantity of massed flower over an area of many acres provided a rare spectacle in those days.
The following dates are of the first flowering of some very fine varieties:

1870 'Sappho'
'Marie Stuart'
1871 'Edward S. Rand'
'James Nasmyth'
'Marchioness of Lansdowne'
'Sigismund Rucker'
1872 'Lady Grey Egerton'
1874 'Garibaldi'
1878 'G. B. Simpson'

There is a constant demand today for nearly all of these plants from a gardening public seeking reliable, hardy flowering evergreens.
The spate of new varieties declined towards 1890, but the younger Anthony took up his father's cudgels and by introducing fresh blood improved the strain further. His criteria were his father's and he also possessed great powers of discrimination. He was so loath to part with his best seedlings that none was seriously commercialized before 1930. The following list includes some of the best of his hybrids. All of them were unhurt by forty degrees of winter frost in 1946-47.

'Mrs. Lionel de Rothschild'
'Joseph Whitworth'
'Mrs. P. D. Williams'
'Mrs. Gomer Waterer'
'Mrs. A. C. Kenrick'
'Mary Waterer'
'Mrs. Philip Martineau'
'Mrs. Furnival' (F.C.C. 1948)
'Mrs. Davies Evans'
'Purple Emperor'
'Souvenir of A. Waterer'
'Windsor Lad'
'William Godfrey'

Large blush pink, fading to white
Large soft pink, ruby blotch
White, chocolate blotch
White, brown-red blotch
Deep purple lake, dark spots
Ivory white, brown blotch
Deep pink, fading suddenly to white in the center
Mauve pink, large truss, fine foliage
Deep pink, yellow eye
Fine rich pink, yellow eye
Clear pink, sienna blotch
Blush-mauve, white stamens
Deep claret
Deep red
Deep red, dark blotch, fine foliage
Salmon, yellow eye
Pale mauve, yellow eye
Blush white, yellow eye

During the 1930's the present company brought to Knap Hill a great number of rhododendron species and hybrids raised in private gardens and other nurseries. They were thoroughly tested in the severe winters of 1946 and 1947 when a considerable proportion of them were either killed or severely injured. The survivors are some of the material with which we work today. Fig. 7. Once again we follow the general principles laid down by the elder Anthony Waterer, but we do not exclude early flowering varieties. These may be constitutionally quite hardy and spring frost is not everywhere so severe as at Knap Hill.

Hybrid rhododendrons at Knapp Hill
Fig. 7. Hybrid rhododendrons at Knapp Hill
Photo Country Life, London

Hybridization has been continued during the 1930's. Promising seedlings have appeared. 'Purple Splendour' has sired a large flowered blush-white, and a cool blush and white with the brilliant young foliage of 'Moser's Maroon', from which no doubt 'Purple Splendour' was derived.
'Blue Tit' x augustinii gave us the low growing 'Sapphire' which, crossed back with augustinii has yielded some wonderful near-blues, as yet unnamed. Their foliage is clean and strong, while their eventual height will probably not exceed five feet.
Pure white rhododendrons, as well as azaleas, have always been great rarities. This year we have given the name of 'Nimbus' to a large-flowered seedling of R. 'Snow Queen' x R. 'Loderi Venus'. The beautifully formed and snow white flowers make this a plant of distinction.
Another recent introduction, although not raised in our nursery, is R. 'Mrs. Arthur Fawcus' a very lovely creamy yellow hybrid of R. kewense x R. caucasicum . The flowers appear in early May, the habit of the plant being robust and compact.
The future has still to show what the old Anthony Waterer hybrids will produce when they are merged with the gorgeous but often tender products of more modern times.

The Knap Hill Azaleas

Until the year 1870 the breeding of azaleas at Knap Hill had not differed in essentials from the breeding carried out at Ghent, Highclere and elsewhere. The very fragrant A. 'Viscosepala' ( A. sinensis x A. viscosa ) is the most distinguished product of those days. The original plant of 1842 is still in splendid health. With the introduction of A. 'Nancy Waterer', however, it became apparent that an individual strain was being evolved.
The elder Anthony crossed several forms of A. calendulacea with A. sinensis . The selected seedlings were many times crossed back with one or other of the parents. Although careful not to use A. sinensis too freely as he considered tender and liable to "burn", he was able with its help to produce a series of large-flowered hybrids ranging in colour from yellow, through orange and apricot to scarlet. The flowers were of firm texture and often had a peculiar "squareness" of shape.

R. occidentale planted about 1860
Fig. 5. Azalea occidentale planted about 1860
Photo Country Life, London

After several years of patient work he succeeded about the year 1871 in crossing A. occidentale , Fig. 5, with A. sinensis and also with certain hybrids of A. mollis x A. sinensis . The seedlings were exceedingly vigorous. The flowers were carried in enormous trusses which opened in late May or early June. Fragrance was unusually strong and the colors were mainly white or pale shades of cream and pink, but some were of a beautiful rich pink. The type plant received a First Class Certificate in 1891 and was named A. 'Albicans' ( A. molle x A. occidentale ).
Azalea 'Albicans' was merged with A. calendulacea x A. sinensis and we believe that it was from such a cross that the beautiful deep pinks with very large "square" shaped flowers were derived. In addition a fine race of double-flowered azaleas was achieved by crossing double Ghents with A. occidentale .
In the course of time parentage became so mixed that it was usually quite impossible to analyze it accurately. Crosses between hybrids became the rule with an occasional cross back with a species. Anthony made few notes. It is said that his sense of criticism was so strong that he was rarely sufficiently satisfied with a seedling to want to see it for more than one season. He seldom increased any one particular hybrid vegetatively, preferring always to sell mixed seedlings. He selected with great discrimination, throwing out ruthlessly anything which did not satisfy his high standards.
There was also a series of seedlings, probably derived from A. speciosa , with red funnel-shaped flowers rather abruptly dilated at the apex. On the whole they were not vigorous, but in recent years strong growing seedlings have appeared - notably A. 'Knap Hill Red' and the large-flowered 'Bullfinch'.
Mention must also be made of a set of unnamed but very distinct and vigorous seedlings which have been known in the nursery for years as occidentale hybrids. It is thought that they may be crosses between several forms of the Azalea occidentale or of A. occidentale x A. albicans . The flowers are very fragrant and are carried in enormous trusses in late May. The color is white or pale cream tinged with varying amount of pink. These are essentially plants for cool and partially shaded places.
The younger Anthony continued to improve the quality of the strain. Generally speaking he raised seedlings from the best of each yearly batch of seedlings, whereas his father had relied mainly on deliberate hybridizations. It was not until 1925 that a serious move was made to propagate individual seedlings by layering and by grafting. In that year Awards of Merit were given to A. 'Marion Meriman', A. 'Knap Hill White' and A. 'Coquette'. The first two of these are, in our opinion, among the finest azaleas grown today.
During the 1930's and again since 1915 intensive hybridization has taken place. The best seedlings have been selected and layered, and, as soon as quantities of individual varieties have become available, a further selection has been made for naming. Assuming that progress is being made in improving a strain, it must be remembered that a newly named variety first flowered in the seedling bed several years before the year of its naming. It is therefore often, but by no means always, inferior to another seedling flowering for the first time in that year and which may in the course of time cause it to be discarded. Now and then exceptions occur, a noteworthy example being A. 'Whitethroat', a double pure white which so far is unique.
Today it is our aim to produce varieties which are capable of making vigorous growth on their own roots and which will ensure a succession of flower from early May until the end of June. We avoid grafting as a means of propagation as far as possible, but we shall use it to increase any good variety which cannot readily be propagated by any other means.
A feature of our azaleas has been the frequent appearance of bronze coloring in the young foliage. This is most marked in the seedling No. 123 in which the pink flowers expand just after the foliage. It also gives great distinction to the very lovely A. 'Mrs. Anthony Waterer' which may well be a hybrid of A. arborescens and A. 'Albicans'. There has also been a tendency towards doubleness in large flowered varieties. Where one or two full-sized extra petals appear as in the pale pink A. 'Gannett' and the salmon-orange seedling Nan 127, the effect is most pleasing.

Original plant of Azalea viscosa planted in 1842.
Fig. 6. The original plant of Azalea viscosa planted in 1842.
It is now 12 ft. x 18 ft. in diameter.
Photo Country Life, London

Quite recently a most promising series of A. viscosa hybrids has appeared. The foliage and habit resemble that of A. viscosa , Fig. 6. The flowers are of medium or rather small size, some of them being semi-double. The colors are white, yellow and pink. Colors which hitherto have been extremely rare and are now occurring more frequently are salmon-red, salmon-pink, pale sulphur-yellow, pure white and late-flowering yellows.
Finally, let it be said that increase of flower size is only one of our aims. We consider that flower shape, texture and colour as well as a strong constitution are of even greater important and that a tendency towards coarseness must be avoided.