This section is from the book "The Florist And Garden Miscellany". Also see: All New Square Foot Gardening: Grow More in Less Space!.
Perhaps no flower is attracting so much attention at the present moment as the Rhododendron. That it is deserving of all the praise which has been bestowed upon it, or that can be said or written in its favour, those who have witnessed the American exhibitions at the Regent's Park during the present season will cordially admit. The general effect of the whole, when entering the tent from the highest ground, was gorgeous in the superlative degree. Many ladies - and their taste in these matters admits of no question - declared it to be a scene of enchantment. Certainly it was magnificent; no collection of exotics, not even Orchids, could afford such a rich display: and when we recollect that the whole of the beautiful varieties of Rhododendrons composing the exhibition alluded to are perfectly hardy; that no expense in the shape of glass, pipes, or fuel, is incurred in their cultivation, we must admit them to possess many claims upon all lovers of flowers.
The skill of the hybridisers has wrought wonders in blending the rich colour of the Indian species with the hardy constitution of the Americans; and the results are the numberless varieties of tint in almost every shade from pure white to the richest crimson, and from pale lilacs to the richest purples, all possessing a sufficient hardiness of constitution to withstand the winters in our climate. A more charming addition to a nobleman's flower-garden than a collection of the best varieties of Rhododendron could not be suggested; and in every garden, however limited, and on the lawn of the suburban villa, are some situations appropriate for their cultivation.
That an impulse has been given to their cultivation is evident; every day it becomes more and more extensive; each succeeding season is adding something to the general stock of information as regards their proper management, which till a comparatively recent period obtained but little attention. As an additional incentive, and one likely to afford valuable information in the cultivation of the Rhododendron, we may mention the publication of an essay on the subject, as an introduction to a catalogue just circulated by Messrs. Standish and Noble, of the Bagshot Nurseries, and which all lovers of this beautiful plant would do well to procure. Besides descriptive notices of many of the more beautiful species of the Pine family, it contains a neatly executed woodcut (10 1/2 by 8 inches) of the celebrated Funebral Cypress, with descriptions of many other rare and beautiful hardy shrubs and trees imported by them from the northern districts of China.
Many persons, say Messrs. Standish and Noble, have been deterred from attempting the cultivation of Rhododendrons from the belief that they only flourish in particular localities. But contrary to this, their extensive knowledge of the habits of the plant enables them to state, " that with a small amount of-well-directed labour, Rhododendrons may be induced to repay the attention of the most ardent cultivator in any part and in almost any locality of Great Britain".
And as a proof of what can be done in situations apparently the most uninviting-, an account of the original condition of their American ground is given, and of the state to which their system of cultivation has brought it. It is thus described: "The soil, which is from twelve to fifteen inches in depth, is a black sandy peat, resting on a clayey subsoil very deficient in vegetable matter, and naturally incapable of producing any crop whatever." The course adopted to induce fertility was this: "The first operation was to drain it from three and a half to four feet deep; it was then trenched two feet deep, and to every acre so treated, from thirty to forty tons of good farm-yard manure was added." Before planting the Rhododendron, however, a root-crop was taken from the land, with a view to exhaust the rankness of the manure. After this treatment, American plants are found to thrive amazingly; but like all crops in very poor soils, they are benefited by the application from time to time of suitable enriching materials".
Till a recent period, the idea of manuring for Rhododendrons was not entertained; but in the nurseries of Messrs. Standish and Noble its application is considered of great importance in their cultivation; and in old beds which have become exhausted, a good dressing of rotten manure is recommended to be applied.
The following passage is worthy of attention: "On all growers of American plants we wish to impress the following suggestion; however simple it may appear, it is the foundation, when practically carried out, of all success in the cultivation of the Rhododendron, and indeed of all fine-rooted plants of a similar character; it is this; Never allow them to become thoroughly dry at the root. When such a condition occurs, the whole structure of the plant is affected, deficiency of vital energy is the result, and the natural consequence of a deteriorated constitution is disease, and possibly death. The Rhododendron and its allies suffer more from excessive dryness than any plants which we recollect; therefore a damp situation, natural or supplied, must be provided for the site of an ' American garden.' If stagnant water is present, drains three feet deep must be employed; and if the natural soil is not suitable, the following compost is recommended: To two parts of sandy loam or peat, or in fact any sandy soil that does not contain much chalk or lime, add one-fourth leaf-mould, one-eighth sand, and one-eighth rotten manure; the whole to be well beaten, and thoroughly incorporated before using.
It would, however, be of great advantage to allow the mixture to remain twelve months, turning it well two or three times during that period".
In situations naturally dry, and where the soil is not suitable, the means to be adopted are these: Deep trenching, and keeping the surface of the beds below the natural soil, in order to prevent the escape of rain or moisture otherwise than by evaporation. " Having decided the outline of your beds, remove the soil a good spade's depth, with all its attached vegetation, to some convenient spot contiguous to your operations; then cart away from 18 inches to 2 feet of the remaining soil, well breaking up the bottom, or trenching it 18 inches deep would be better still. Upon this cast in the surface-soil previously removed, well chopping it as the work proceeds, filling up with a sufficient quantity of prepared soil, that, after settling down, it shall be a few inches below the natural surface. During dry weather, after the beds are planted, the surface should be kept constantly stirred with the hoe and rake, for the double purpose of preventing the growth of weeds, and retarding evaporation. Should an excessively dry season occur, the whole surface of newly-planted beds may with advantage be wholly covered with short grass from the lawns.
It will at least prevent the necessity of the frequent use of the watering-pot, the application of which in all out-door gardening is a practice ' more honoured in the breach than in the observance.' If the beds are situated in the neighbourhood of trees, they are sure to be invaded by a legion of roots, which, if allowed unmolested possession, will in a few seasons appropriate the whole of what you had intended for your favourites. But as we recommend American plants in such situations to be replanted, and the soil trenched to the depth of two feet every autumn, and every third or fourth year the whole mass of soil trenched to the bottom, there will not be much to fear upon that point; and the mass of soil, by being constantly rendered permeable to the autumn rains, will always contain a large amount of moisture. There need be no fear of the plants suffering from removal, as Rhododendrons can be transplanted with perfect safety even after they have attained an immense size, and particularly so when they have constantly been subjected to such treatment".
As a proof of the truth of this assertion, we may mention that the whole of the magnificent collection comprising the exhibition at the Regent's Park were removed from the nurseries a few weeks before blooming. Some of the large standards exhibited there are reported to be more than forty years old!