JARS v46n3 - Rhododendron hanceanum 'Nanum'

Rhododendron hanceanum 'Nanum'
Origin and History
Brian O. Mulligan
Kirkland, Washington

This excellent dwarf rhododendron is frequently mentioned in articles on this subject, usually with much praise for its valued habit, as well as the profusion and color of its flowers, yet I do not believe that its full history has been published anywhere. I hope to fill in this gap here and record the facts of its origin for the benefit of present and future growers of this plant, as well as authors of books on rhododendrons.

The best account at present is to be found in Dr. H.H. Davidian's book, The Rhododendron Species, Vol. I, Lepidotes , published by Timber Press, Portland, Ore. (1982). Here he states: "It appeared in cultivation among seedlings raised from R. hanceanum seed (no. 4255) collected by Wilson in southwest Szechuan". But no record as to which garden produced it or when.

To find that information we have to refer to the Notes of the Rhododendron Society , published privately but probably in London by this small group of amateur rhododendron growers in the British Isles, from 1916 onwards, during the First World War. These Notes have fortunately been reprinted by the Pacific Rhododendron Society, Tacoma, Wash., in 1976. A copy is in the Natural Sciences library at the University of Washington in Seattle where I was able to consult it. Volume I, Part 5 (1919), contains an article on pages 233-235 by Mr. Hugh Armytage Moore on the new Chinese species he was growing in his garden at Rowallane, Saintfield, Co. Down, N. Ireland. The following quotes his article.

"In R. hanceanum we appear to have a plant that represents a stumbling block to many a gardener and bears in consequence a somewhat evil reputation. Here it clearly demonstrates its dislike of low-lying sunny positions, and appreciation of a sloping, well-drained bank where little or no sun can reach it, and where its roots penetrate beneath a neighboring stone. In such a position the somewhat pendulous growth and extreme freedom of flower is well displayed, and the plant generally receives the admiration which it rightly deserves. From seed of this species there has been raised here a pygmy sport - just a dark green cushion bursting with creamy-yellow flowers, a mossy saxifrage on a grand scale. One little mat, nine years of age, though perhaps one foot across, is still beneath two inches in stature, and when covered in bloom represents as pretty a picture as one could hope to find in any rock garden."

This places the date of raising the plant at 1910. Mr. Moore does not say where he obtained the seeds of R. hanceanum , but it could well have been from Mr. J.C. Williams of Caerhays Castle, Cornwall, since in Part 3 of these Notes , published in 1917, Mr. Williams includes R. hanceanum among the list of species growing there, with the Wilson numbers 882 and 4255. Wilson had collected some in October 1910, in the Mupin region of Szechuan.

Following this very definite information as to the origin of this dwarf form, the next comes in an article by Lady (Phylis) Moore, wife of the then director of the Botanic Gardens, Glasnevin, Dublin, Ireland, but no relation to Mr. Hugh Moore of Rowallane. The article is entitled "The Garden at Rowallane", and was published in the quarterly New Flora and Silva , Vol. II, No. 3, (April 1930) by Dulau and Co. of London. This journal unfortunately did not survive the war years and concluded after Vol. I No. 10. To quote Lady Moore: "a very interesting pygmy form of R. hanceanum grown from seed, four inches high at 16 years of age". However, from Mr. Moore's own statement of 1919 we know that in 1929 the plant must have been 19 years old, if that was the year of Lady Moore's visit to Rowallane.

Pursuing the subject we next come to a book written by A.T. Johnson who had a well-known small garden in North Wales between the two wars and wrote several books about it and plants therein. This is A Woodland Garden and was published by Country Life Ltd. in London and Charles Scribner's Sons in New York in 1937. A footnote on p. 160 reads: "A pygmy form of R. hanceanum , which has only just flowered, is even better (than R. lutescens ), the blooms being like those of R. oreotrephes in a bright daffodil yellow." He illustrates it on p. 146 with one of his own black and white photographs, for the first time so far as I know, showing a very free-flowering small plant perhaps 8-9 inches tall and 10-12 inches wide. In a later book, The Mill Garden , published by Collingridge, London, in 1950, Mr. Johnson enlarges on this plant, on p. 147, when discussing dwarf rhododendrons: "Two color forms of the neat, densely dome-shaped R. hanceanum nanum *, a hardy free-flowering and contented little shrub, bringing in that welcome touch of yellow where mauves and purples predominate." He does not mention the source of his plant, but it could well have been from the famous garden of Lord and Lady Aberconway at Bodnant, only a few miles away.

There are also four notes concerning Rhododendron hanceanum nanum in several issues of the Journal of the Royal Horticultural Society, London, published between 1939 and 1964. The first of these is by Francis Hanger, then head gardener to Lionel de Rothschild at Exbury, Hampshire, writing about "Miniature Rhododendron Species" in Volume 69 (1939). Here he says: "My favorite small-growing yellow rhododendron is the dwarf form of R. hanceanum which does not exceed nine inches in height and is now quite 18 inches through at Exbury." The second is in Volume 81, p.475 (1956), on "The Garden at Rowallane", by Leslie Slinger, one of the owners of the Slieve Donard Nursery at Newcastle, Co. Down, Northern Ireland, not far from Mr. Moore's home at Saintfield in the same county. He remarks: "Of the small shrubs in the walled-in garden, some of the most outstanding are...and both the cream and sulphur-yellow forms of R. hanceanum nanum ". So in the 1950s and no doubt slightly earlier, we have records of two different color forms of this plant in cultivation, which apparently originated at Rowallane.

The third note is contained in an article "Colour Schemes for Small Gardens" by David Wright, in Volume 86, p.219, and Fig. 60, (May 1961): "And dwarfest of all are R. hanceanum nanum with azalea-like pale primrose to cream flowers". The black and white photo by J.E. Downward shows two or three flowering plants in a group at the front of a border of shrubs. They appear to be about two feel tall and three feet or more in width. They do not look at all like the dwarf plant of our earlier authors.

The last note I have found in the R.H.S. Journal is contained in an account "Gardens and Gardeners in Ireland" by R.C. Jenkinson, in Vol. 89 (Sept. 1964), this installment covering Rowallane. I quote: "And then in an open bed one of the specialités de la maison, R. hanceanum nanum , a bushlet of no more than nine inches, with creamy-yellow flowers in profusion. I do not know where Mr. Moore obtained it, but this is the original true plant. A rock garden gem." Note that only one color form is mentioned, just eight years after Leslie Slinger's visit. Mr. Moore died, I believe, in Dec. 1954. In the following year the property was taken over by the Ulster Land Fund and later passed on to the National Trust of Great Britain which now controls and maintains it.

Then there are Peter Cox's remarks in his Dwarf Rhododendrons (Macmillan, New York, 1973), p. 179. "'Nanum' is possibly a clone but more probably applies to several low compact variants. It is very dwarf with small leaves and bright yellow flowers and is a free-flowering charming little plant, being one of the best yellow dwarfs". I think we can certainly consider the original plant a clone and his description meets its characters. There is a black and white photo of a flowering plant on p.34.

Finally we have Dr. Davidian's account of this form in his The Rhododendron Species, Vol. I, Lepidotes , (Timber Press, Portland, Ore., 1982), p.343. "R. hanceanum 'Nanum'. This plant has long been known as R. hanceanum var. nanum . It appeared in cultivation among seedlings raised from R. hanceanum seed (no. 4255) collected by Wilson in southwest Szechuan. The true 'Nanum' is a dwarf compact shrub, 8-15 cm. (3-6 ins.) high, and up to 25 cm. (10 ins.) wide, with small leaves 2-3.5 cm. long, 1.0-1.6cm broad, and with yellow flowers. It is free-flowering and exceedingly charming when covered with funnel-campanulate flowers in clusters of 4-7." His color plate 67 shows a small flowering plant covered with primrose-yellow flowers typical of this clone.

R. hanceanum 'Nanum', Rowallane
R. hanceanum 'Nanum', Rowallane, Co. Down, N. Ireland.
Photo by Margaret Mulligan

There is no doubt, however, that the plant can easily exceed the dimensions given by Dr. Davidian, as the Kodachrome taken by my wife, Margaret Mulligan, on June 5th, 1983, at Rowallane clearly shows. I quote from my notes made in the garden that day: "In the walled garden we were entranced by the sight of Rhododendron hanceanum 'Nanum' in full bloom on top of a wall, the flowers pale yellow, the plant a good three feet across and 18 inches tall". We were taken there by Dr. Charles Nelson, taxonomist from the National Botanic Garden, Glasnevin, Dublin, to whom we are indeed grateful for transportation and this and other experiences on the same tour.

There is also a clone 'Canton Consul', raised at the Savill garden in Windsor Great Park, Berkshire, which received an Award of Merit when shown by the Crown Estate Commissioners at an R.H.S. show in London, April 16, 1957. The official description of this clone, as published in the R.H.S. Journal the following year (Vol. 83, p.36) reads as follows: "Being dwarf in habit this rhododendron is admirably suited for the rock garden. It is free-flowering, annually displaying terminal inflorescences, the flowers of which are cream color and the buds a contrasting shade of creamish-green.'' This is not a very full description, saying nothing about the dimensions of the plant, its foliage or flowers. It is briefly mentioned in the revised 8th Edition of Bean's Trees and Shrubs Hardy in the British Isles , Vol. Ill, p.679 (1976), and in the Rhododendron Handbook of the R.H.S. (1980). The contrasting colors of the buds and flowers seem to be the best distinguishing characters, and probably also its habit of growth, although I have no information on this point. The name 'Canton Consul' was given to it later, to distinguish it from Mr. Moore's original 'Nanum'. The reason for this name lies in the fact that Mr. H.F. Hance, after whom the species was named by W.B. Hemsley, was at one time British Consul at Canton, China. No doubt Sir Eric Savill was the author of this cognomen, since he was then in charge of the plantings at Windsor Great Park.


Since writing the foregoing Dr. Nelson has very kindly sent me copies of other journals pertinent to this enquiry. One, from Irish Gardening of June 1919, contains an article written by Mr. Moore, "Rhododendrons at Rowallane in April." This repeats his statement of the same year published in the Rhododendron Society's Notes as to the origin of this dwarf plant. The second item comprised two letters published in the now defunct British Journal Gardening Illustrated in July 1939. The first, on p. 434, signed by an anonymous "Sylvaticus", praised the good qualities of Rhododendron hanceanum pygmaea and was accompanied by a black and white photograph of a plant in full bloom. Two weeks later Mr. Moore replied to this in the same journal, (p.486), stating that the plant had been raised at Rowallane about 20 years previously (this should have read about 30 years, remembering his original date of 1910), and "subsequently distributed to a few personal friends under the name of Rhododendron hanceanum var. nanum ." He continues: "Before its death about ten years later, it had been propagated both by seeds and cuttings." If true, this would place the plant's death in about 1920, but against that we have Lady Moore's statement of April 1930 that she saw a thriving plant of some size at Rowallane the previous year. So Mr. Moore may not have been quite accurate in remembering the date of the original plant's decease.

It is quite possible that the anonymous "Sylvaticus" was none other than A.T. Johnson, who had mentioned and illustrated this plant in his book A Woodland Garden , 1937, only two years before this correspondence appeared in Gardening Illustrated , but this information we are now unlikely to learn.

Dr. Nelson also sent me a page from a Donard Nursery Company's catalogue of about 1940 which lists both Rhododendron hanceanum and its pygmy form, so it was in the British nursery trade by that date and probably earlier. A thriving plant now some 15 years old can be seen in the Rhododendron Species Foundation collection at Federal Way, Wash.

It is high time that this distinct little clone be properly described and registered as 'Rowallane'.

Bibliography (arranged chronologically)
1.  Rhododendron Society, Notes . Privately published; ? London (1916-1931). Reprinted by Pacific Rhododendron Society, Tacoma, Wash. (1976). H.A. Moore, in Vol. I, pt.5, 233-235, (1919). Rhododendrons at Rowallane .
2. Irish Gardening , XIV, No. 160, 81-82, (Dublin, June 1919) H.A. Moore; "Rhododendrons at Rowallane in April".
3. New Flora and Silva , Vol. II No. 3 (April 1930). (Dulau & Co., London). Lady Moore; "The Garden at Rowallane".
4. A Woodland Garden , A.T. Johnson (Country Life Ltd., London, and Charles Scribner's Sons, New York, 1937).
5. Journal of R.H.S. , London. Vol. 69, (Jan. 1939). F. Hanger; ''Miniature Rhododendron Species".
6a. Gardening Illustrated ; Vol. 61,434 (London, July 8, 1939). "Sylvaticus"; "A Remarkable Rhododendron".
6b.  Loc. cit. 486, (July 29, 1939). H.A. Moore; "A Remarkable Rhododendron".
7. The Mill Garden , A.T. Johnson (Collingridge. London, 1950).
8. Journal of R.H.S. , Vol. 81,475, (Nov. 1956). L. Slinger; "The Garden at Rowallane".
9.  Loc. cit., Vol. 83,36, (1958). Anon. Clone, 'Canton Consul'.
10.  Loc. cit., Vol. 86,219, (May 1961). David Wright; Colour Schemes for Small Gardens .
11.  Loc. cit., Vol. 89,369, (Sept. 1964). R.C. Jenkinson; Gardens and Gardeners in Ireland; Rowallane.
12. Dwarf Rhododendrons , P.A. Cox (Macmillan, New York, 1973).
13. Trees and Shrubs Hardy in the British Isles . 8th Rev. Edn., Vol. III, 679 (John Murray, London, 1976). D.L. Clarke; "Rhodn.-hanceanum nanum & 'Canton Consul'".
14. The Rhododendron Species, Vol. I, Lepidotes . H.H. Davidian (Timber Press, Portland, Ore., 1982). R. hanceanum 'Nanum', p.343 & pl.67.

Brian O. Mulligan is Director Emeritus, Washington Park Arboretum, Seattle, Wash., and Vice-President, Royal Horticultural Society, London, U.K.

* Editor's Note: Under the Cullen and Chamberlain classification of genus Rhododendron , dwarf forms of hanceanum are not considered to be different enough botanically from hanceanum to warrant a separate sub-unit name. In recognizing the horticultural value of retaining the name that distinguishes the plants previously known as hanceanum var. nanum , the RHS Horticultural Revision utilizes the name hanceanum Nanum Group. 'Nanum' is not a registered name.