Rhododendrons at Homebush
New Zealand Rhododendron Association
The following is a brief description of the cultivation of rhododendrons growing on the Homebush Estate, in the County of Malvern Canterbury.
This Estate is part of one of the original runs which once consisted of an area of over 30,000 acres. The run through the years has been subdivided into many farms and considerable portions of it have been sold to farmers outside the Deans family. However the original homestead block is still in the hands of the writer of this article. Messrs. John and Douglas Deans, who are both keen rhododendron enthusiasts, have properties adjoining and started their collections previously to that of Homebush.
Climatically this district is well suited to the growth of both rhododendrons and azaleas as well as most hardy garden shrubs. It is also noted for the variety and number of trees, both coniferous and deciduous which were planted 75 to 80 years ago, and which were doing exceptionally well until the great gales of 1945. During the winter of that year these gales blew down most of the plantations and large numbers of the specimen trees around the Homesteads.
The situation of these properties is about 36 miles due west of Christchurch, and the elevation runs from about 750 to 850 feet above sea level. Being close to the Southern Alps, the rainfall is a good deal heavier than on the adjacent plains of Canterbury. The annual rainfall over a number of years has averaged about 36 inches. The distribution of this rainfall however, is an important point, December being the wettest month of the year. This generally means that there are more dull days at this period of the year than in the coastal areas, a factor which is beneficial to the genus rhododendron. It is a well known fact that in the Himalayas where most of the rhododendrons come from, conditions are almost continuously cloudy or misty during their flowering season. The winters are comparatively cold with snow at times, and falls of up to two feet have been recorded in the past, and it is usual to have several light falls during each winter period. Unseasonable falls sometimes occur and have been recorded in every month of the year. Frosts also area regular occurrence and up to 25 degrees are experienced in hard winters. The late spring frosts such as that which took place at the end of September 1949 do great damage to the blooms and young growths of rhododendrons but it is remarkable how soon the plants recover. Winds also are a source of worry to growers as Northwest gales occur frequently especially in the spring and early summer. Even in winter time they can take place and most of the damage done in 1945 was caused by gales which were experienced during the winter, one before a heavy snowfall of over 2 feet and one about six weeks later.
Luckily the properties which are being described are on low hills which give protection to most of the rhododendron sites. It is wonderful however to see the good growth of the damaged shrubs which were so woefully broken down in 1945 when trees fell over them. In many cases the rhododendrons were bent over and not broken, so that they could be straightened up when the tree limbs and trunks were removed. Out of the Homebush collection consisting of some hundreds of planted out specimens only six or seven were totally destroyed, and ones which were severely damaged have in most instances put on a very strong growth which is now beginning to flower.
Rhododendrons of the commoner sort such as Ponticum were planted many years ago and have grown into large straggly bushes which are covered with masses of flowers almost every year. The main collections of the newer kinds were however started from about 1925 onwards at "Kirkstyle" the property of Mt. John Deans and "Rowallan" whose owner is Mt. Douglas Deans. There were some common ones at Homebush dotted about the grounds, but the writer did not really do much in their propagation until he returned from England in 1927. The Kirkstyle garden is situated on a hill which rises to a height of about 75 feet above the adjoining fiats and the principal planting was first of all done amongst treys on a northern face, but latterly quite a number of good sorts were placed on a very steep slope which faces almost due south. The main planting on the northern face did quite well considering that the soil is a rather stiff clay, which holds water for considerable periods during the winter and spring. However, the gales which occurred in 1945 blew down most of the trees on this site, with a consequent deterioration in the health of the plants. Quite a number of the best sorts have been removed since the wind, to the Riccarton property of Mr. Deans, but the climate there is not nearly so suitable as at Kirkstyle and the rhododendrons are now having rather a hard struggle to survive. Some recent importations also are having difficulty in becoming established. On the south slope the soil is a much freer nature with a certain amount of shingle mixed with it, and practically all the plants are in excellent condition and this site with its shade and shelter is ideally situated for their culture.
At Rowallan also there is quite a variation in soil and the first planting took place on an eastern slope amongst young plantations of conifers and deciduous trees. This place was fairly shingly and dried out rather quickly in some seasons, so that many of the rhododendrons had to be moved down to fiat ground near the house. Here they have recovered and are now thriving exceedingly well and give promise of becoming a very valuable collection in a few years time.
The main planting began about 1925 by the purchase of some very good sorts from Ivory's nurseries. Calophytum, sutchuenense Argyrophyllum and others of equal merit were then bought. These have been added to, by importations from Ilam and nurseries both in the North and South Islands. At the present time almost all of the rhododendrons are in perfect condition, and many of the large leafed varieties have flowered at a comparatively young age. Sino-grande Elsae, Falconeri and Fictolacteum being some of the flowering ones, which make a very fine shore dotted amongst the trees. Quite a number of the smaller species, such as Racemosum, Russatum, Floccigerum, Sperabile and others are growing in a border by the house, and doing exceedingly well. They are eminently suitable for growing in a small garden, where the stronger growing ones would be definitely out of place. The main lesson in these two gardens is how well rhododendrons will do if moved about from unsuitable conditions to suitable ones or vice versa, also how quick is their recovery in the first instance.
Coming now to the modern rhododendrons growing at Homebush, these were started by a gift of some of Forrest species which were grown from seed sent back from one of his Himalayan expeditions. These were grown at Ardingly in Surrey and given to the writer by the late Lord Wakehurst, and were imported in 1927 together with some good Dutch hybrids. The collection was increased by a very generous gift of many hybrids from Dam by the late Mr. Stead. Since then many others have been obtained from various sources until at the present time there are about 600 planted out in native bush and various sites near the house. The ones in the bush are ideally situated as the dark foliage of the native trees gives them a perfect setting. Others planted alongside a stream; and an artificial skating pond also shows to advantage when reflected in the brown colored peaty water. The soil conditions at Homebush vary considerably in the many localities where the rhododendrons are planted. Some places are on a stony hillside, others in clayey conditions, and more in river silt. In the latter site the growth is best and a section of this river flat has been used as a nursery, with good results. It is remarkable however to find the plants generally in such a healthy state over the whole area which seems to point to the fact that climate is a more important factor for their growth than is soil conditions.
There are some exceptions however to their healthiness, particularly in the case of the smaller alpine varieties which have been rather difficult to establish. In some instances they have died, whilst the surviving ones are in poor shape just struggling along with a minimum of growth. The more tender varieties of the Lindleyi Nuttallii series also although showing good growth are hardly worth cultivating. They have produced flower buds both at Rowallan and Homebush but so far have failed to flower, even under sheltered conditions. Frost seems too severe to allow them to develop into the blooming stage. The incidence of frost damage is hard to understand, as this year after a severe frost early in the winter, which did a lot of damage to many garden plants, there has been a very good flowering of many of the early semi-tender kinds of rhododendrons. Generally speaking much more damage has been caused by frost after a snowfall, as the cold temperatures seem to penetrate under tree shade, to a greater degree than in a bare frost.
A fine example of R. giganteum has flowered at Homebush on two occasions in its 25 years of life. The best flowering took place in 1949 when it commenced to bloom in August and continued until the end of September. Then the disastrous frost occurred which cut the blooms to pieces and also destroyed the new growth and seed capsules. This was unfortunate as it was hoped to have seed of this fine species for propagation by our Society.
R. sinogrande also has made excellent growth in some years and leaves up to 26 inches in length have been measured on it. But although over 20 years old it has not so far deigned to flower. The strong growth of these large leafed varieties of rhododendrons seems to militate against their early flowering. They should however, in the long run, produce blooms of excellent size and quality. Some of the finest scarlet and crimson hybrids, such as 'Cornubia', 'Gill's Crimson', sperabile , delavayi cross and many others, and the Ilam crosses both yellow, pink and white, at present make a fine show, and give promise of an ever increasing delight for years to come.
Many species such as barbatum , decorum , diaprepes , sperabile , chasmanthum , yunnanense , to mention only a few, are thriving and give a pleasing variety to a representative collection.
In spite of some drawbacks to their cultivation, there is no doubt that rhododendrons will do extremely well in the locality described, especially as so far they have been singularly free from pests and diseases. They should and will do equally well along the foothills in the South Island, where the winters are sufficiently cold and where the rainfall is adequate, and well distributed throughout the year.