JARS v52n3 - 70 Years On: Rhododendron and Azalea Registrations from Ilam

70 Years On: Rhododendron and Azalea Registrations from Ilam
University of Canterbury, Christchurch, New Zealand
Kathryn Millar
Leeston, Central Canterbury
New Zealand

Writing in the 1947 Royal Horticultural Society Yearbook , the late Edgar Stead wrote of his first efforts with hybridizing rhododendrons in 1918. The resulting plants, both rhododendrons and azaleas, have been widely planted in New Zealand gardens and also used in the hybridizing programmes of others, in particular that of the late Mollie Coker who lived next door. Registrations in other countries also indicate from time to time the use of Ilam raised parents; there was one in the ARS seed list recently using Rhododendron 'Irene Stead'.

What is exciting in 1998 is that the University of Canterbury have this year registered 12 plants bred in more recent times, and opportunities will be given to visit Ilam at the time of the New Zealand Rhododendron Conference this year from Oct. 27th to 30th. The conference is to be based in and around Christchurch, Canterbury, which is in the south island of New Zealand. Before writing further about these new registrations, it may be prudent after 70 years to give a little background here for enthusiasts who may have no knowledge of the Ilam Garden and Edgar Stead.

The Ilam property was settled by J.C. Watts Russell, a wealthy Canterbury pilgrim, who had arrived with the first four ships. During his ownership trees were established and the site developed. However, by the time Stead (a noted ornithologist) purchased 55 acres in 1914, the homestead had been burnt down, but, as Roland Stead wrote in a recent article for the New Zealand Rhododendron Association Bulletin: "It presented a park-like appearance, with paddocks, streams and nicely planted trees...an ideal site for development with smaller garden plants such as rhododendrons and azaleas, and their associated trees such as maples, magnolias, etc. With the introduction of these plants in mind, my father travelled to England in the 1920s and '30s and became a frequent visitor to some of the well known rhododendron gardens of the time, and stayed at Caerhays Castle, Bodnant, Muncaster Castle, Leonardslee, and particularly Exbury."

In 1925 he landed 490 plants in his garden through the generosity of the English enthusiasts. As well as the importations, a large number of hybrid plants were being raised, R. griersonianum and R. griffithianum being amongst the species used. (One must remember this was long before the days of "yak", etc.)

Fred C. Galle in Azaleas writes, "Mr. Stead recombined the Knap Hills with R. calendulaceum (from eastern USA), R. viscosum (the swamp azalea or swamp honeysuckle of eastern USA), and R. molle in the early development of the Ilam hybrids, for new colours, increased truss size and fragrance. Only the lighter coloured hybrids were fragrant. Some have been named since and introduced into commerce."

David Leach reported that the Ilam azalea flowers have substance and on average are more durable in hot weather (possibly R. calendulaceum hybrids or forms). The ancient Ghent azaleas used in the hybridizing, which were shifted to Ilam from another Christchurch garden, are still there today.

Stead was also a pioneer in the use of sawdust, this in the 1930s when general opinion foresaw disastrous consequences from such a practice.

Roland also noted, "Father used to raise a batch, say, of 14 or so seedlings from one crossing, keep the two best for the garden, give or sell another two, and destroy the rest." Countless hybrids have been registered since the days of Edgar Stead, but given the durability of his best hybrids it would seem such a policy could be still a useful rule of selection.

Sir Cracroft Wilson of the Cashmere Estate, situated on the hills of Christchurch, had brought to New Zealand seeds of a red R. arboreum and raised a number of plants. Wilson had been in India and perhaps there lies a clue to the origin of the seeds - who knows. From these, two plants were selected which showed deep blood red colour and exceptionally large trusses. Edgar Stead used these plants, but reported that "after waiting 12 years for the seedlings to flower, none was as good as the parents" (RHS 1947 Yearbook ). He used the better of the original plants, which he describes as the more tender, for much of his hybridizing. Visitors to Ilam Gardens can still see the old plant of R. arboreum ssp. zeylanicum used in the hybridizing for mid to late season flowers. Time has changed much in nomenclature and Peter Cox in The Larger Rhododendron Species notes that plants once described as R. arboreum var. kingianum are in all probability R. arboreum ssp. zeylanicum , the two having often been confused. The flowers of var. kingianum are said to be later than ssp. zeylanicum , and hidden in the mists of time are the observations of Edgar Stead as he deliberated on flowering times (he mentions this in his notes), and their relevance to his hybridizing. Also down by the creek is the tall and ancient R. arboreum now labeled as kingianum , one of the plants from Cashmere Estate. Mrs. Cracroft Wilson was apparently not at all pleased that her husband had been persuaded to part with this precious plant, which even then was quite large. The overhead lines for the Riccarton tram had to be raised for the lorry to pass safely underneath. 'Ilam Cornubia', a large early flowering blood red is a result of crossing the good red R. arboreum with 'Shilsonii' ( R. thomsonii x R. barbatum ).

'Ilam Alarm' is R. arboreum ssp. zeylanicum x R. griffithianum . The Canterbury Rhododendron Society collection at Orton Bradley Park on Lyttelton Harbour will also be included in the conference, and visitors may see there a newly planted collection of the Scarlet King Group: 'Ilam Alarm' x R. griersonianum . The original plants at Ilam are now getting very old, and while the university staff are making every effort to rejuvenate where possible, it seems wise to preserve these plants at another site in Canterbury.

An Ilam raised plant of particular note is the wonderful fragrant rich pink 'I.M.S.' or 'Irene Stead' which Edgar Stead named after his wife Irene Mary Stead. The result of crossing two unknown pink selections from the Loderi Group, it was awarded an AM by the RHS in 1987. In 1981 Roland Stead registered 'Ilam Cream', a Loderi seedling which is a strong grower, pink in bud with large trusses of scented cream flowers suffused with pink. Recently a wonderful cerise mentioned by Edgar Stead in his 1947 notes has been named 'Ilam Cerise' ('Lady de Rothschild' x R. arboreum ) and is now available in commerce in New Zealand; free flowering with a large arresting truss, it has crimson flowers with a white throat, and a small red eye.

'Tupare' ( R. nuttallii x R. lindleyi ) bred before 1950 is another great garden rhododendron from Ilam with large trusses of tubular campanulate flowers, creamy pink in bud and opening white with a yellow basal blotch. It is strongly scented. A plant grown by Sir Russell Mathews at Tupare, Taranaki, N.Z., was registered by Graham Smith in 1985. The original plant is still in the Ilam garden. Rhododendron nuttallii x R. lindleyi , 'Stead's Best'*, is a plant sought by the discerning rhododendron grower in New Zealand. A vigorous plant, it is a reliable bloomer producing scented white flowers of good substance with a yellow throat. More than one plant of 'Tupare' and 'Stead's Best' are contained in the Canterbury collection at Orton Bradley Park.

The 1934 description of the flowers and foliage of R. giganteum (now known as R. protistum var. giganteum ) seems to substantiate the thought that this was one of the earliest flowerings of R. protistum in cultivation. This gives rise to conjecture whether the plant that was removed to allow the building of a service drive at the staff club (originally the homestead) was the plant. (There are others still on site.)

When Edgar Stead died in 1949 the property was sold and became part of the site for the relocated University of Canterbury. The sale deed included a clause that the garden be maintained as a park, and the university had faithfully adhered to this, which brings us to the current story.

When the university took over, a great number of plants were raised from open pollinated seed. There were also a series of severe storms in the 1970s resulting in the loss of many trees including oaks and many rhododendrons smashed underneath. The resultant clearance altered the garden's appearance.

About that time a breeding programme was undertaken by Peter Cadigan and the grounds staff. Peter had previously served overseas with the Commonwealth War Graves Commission and had become superintendent of grounds for the University of Canterbury in the early 1970s. At the time the new 75-hectare campus was being landscaped and planted, requiring many plants. What more appropriate than rhododendrons and azaleas? One example was the crossing of a dead white flowered, sprawling form of the Loderi Group with R. williamsianum .

'IIam Canary' [( R. campylocarpum x R. discolor , an Exbury plant) x 'Loderi'] was crossed with some of the other yellow hybrids in the garden, e.g., Steads' R. dichroanthum hybrids. A number of these have been grown on within the grounds for evaluation of plant habit, sun tolerance, foliage, etc., and now the University of Canterbury, encouraged by the Canterbury Rhododendron Association, have selected six plants for registration. All have the prefix "Ilam" and are 'Ilam Moonglow', 'Ilam Moonlight', 'Ilam Glory', 'Ilam Serenity', 'Ilam Springtime', and 'Ilam Beauty' and have produced clear yellow, well formed trusses on a compact hardy plant.

'Ilam Galaxy Sunburst'
'Ilam Galaxy Sunburst'
Photo by Peter Cadigan

The trial beds of azaleas have been a spectacle each spring for some years and contain many colour blends not seen before. Among those in the process of being registered are both vivid and bi-coloured pastel tones. The azalea registrations have the prefix "Ilam Galaxy" and are: 'Ilam Galaxy Appleblossom', 'Ilam Galaxy Cascade', 'Ilam Galaxy Celeste', 'Ilam Galaxy Dawn', 'Ilam Galaxy Firestorm', 'Ilam Galaxy Radiance', 'Ilam Galaxy Stardust', 'Ilam Galaxy Sunburst', 'Ilam Galaxy Sunlight', 'Ilam Galaxy Surprise', 'Ilam Galaxy Virgo', and 'Ilam Galaxy Volcano'. The trial beds will be open for viewing during the Christchurch conference, and a display of blooms from the registered plants will also be staged.

Cox, Peter A. 1990. The Larger Rhododendron Species . Portland: Timber Press.
Galle, Fred C. 1985. Azaleas . Portland: Timber Press.
Stead, Edgar F. 1997. Rhododendrons in New Zealand. The RHS Rhododendron Yearbook 1947, No. 2 .
Stead, Roland. Ilam Revisited. The New Zealand Rhododendron Association 50th Jubilee Bulletin .

Information; Roland Stead, Ross Wilson, Peter Cadigan and Ron Coker.

* Name is not registered.

Kathryn Millar is the past editor of the New Zealand Rhododendron Annual Bulletin and a member of the New Zealand Rhododendron Association Council, with an interest in garden history and the preservation of plants of genetic importance. Her article is contributed on behalf of the Canterbury Rhododendron Association.

The New Zealand Rhododendron Association Conference will be held Oct. 27-30, 1998, in Christchurch at the Hotel Grand Chancellor. Tours and speakers are planned.