This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
Foremost among evergreen shrubs stands this beantiful genus; beautiful in its foliage and habit of plants, but beautiful, gorgeous and magnificent in its flowers. This is true of our native varieties; for what more beautiful than a good variety of Catawbiense 1 It is true of the European species, and more true still of the beautiful scarlet species from the Himalayas, and the innumerable species from Sikkim; Borneo, also, producing some magnificent epiphytal species. The few remarks I am about to make will be in reference to our native species, or such as may be crossed to advantage with them. Of late these beautiful plants are attracting some attention, ,but unless care is taken in selecting varieties of hardy parentage, disappointment is sure to follow. All our American species and varieties may be cultivated. Among the best are the following: R. Catawbiense,* R. maximum, R. M. album, R. M. purpureum, R. punctatum, R. azaleoides, R. Cataesbaei, R. Californica, Ac. Here is a very nice list to begin with, and the three first are as good as many of the finest foreign varieties. The first, R. Catawbiense, has been used in Europe in crossing with the eastern species more than any other, it possesses so many good qualities.
The habit and foliage are good; it has a large finely-formed truss of bloom, the individual flowers well-shaped. This crossed with arborea produced altaelarense, the first scarlet hybrid rhododendron that appeared in England, and hardy; it was raised at Highclere* in Hampshire, and caused quite a sensation among the admirers of this flower at the time. Many other good seedlings were subsequently raised, but the great fault of these first seedlings, was their early season of blooming, being generally destroyed by cold winds or frosts; latterly, however, this has been overcome by repeated crossing with the late blooming species, until we have now varieties sufficiently late, and of fine shape and color. If any of our cultivators would like to experiment in this way, take a plant of R. Catawbiense, or R. maximum, and in place of crossing with a hybrid of the first generation, as altaclarense, cross with the third or fourth generation (having one of these as parent in each cross); such would be pulchellum, Towandii, elegans, Standishii, Mrs. Loudon, Ac., the offspring will be a seedling nearly as hardy as its American parent; and, by following this up, a race will be found as hardy as our native varieties, with brilliant, finely-shaped flowers.
There is another great advantage in this, whilst the first and second generation of hybrids take many years to bloom, the third and fourth bloom at a very early age, and in the greatest profusion. Many persons imagine they can purchase rhododendrons in Europe at a very cheap rate; so they can such varieties as are usually planted in woods as shelter for game, and principally composed of the poorest varieties of Pontica; but a grower of such plants would no more take these, than an orchardist would a lot of seedling crabs to plant his orchard with; when a good variety is produced, it is increased by grafting, and as these require a little more care than common things, good varieties of rhododendron command a good price. Varieties which are increased in this way will command two-and-sixpence to three-and-sixpence each, whilst rarer varieties run a great deal higher.† Not their best seedlings can you get; breeders of rhododendrons, like raisers of other things, know from the parentage what to expect, and by examining the foliage they can pick out all the finest and best varieties with scarcely a mistake.
True, raisers are sometimes deceived in this way, but it is not often; the callings of the beds are then sold cheaply to some of our bargain-hunting gentlemen, when they doubtless think they have succeeded admirably. From parentage they cannot judge unless acquainted with rhododendrons and their breeding. To illustrate this, take Catawbiense and cross it with.altaclarense, and the result will be a good scarlet hybrid; but cross the latter with a similar hybrid, as pnl-cherrima, and the result will be a race of the most miserable and worthless hybrids. I know of no class of shrubs where more care or judgment is necessary than in this very one, that good varieties alone may be selected.
*The variety figured some time back in the Horticulturist, Judging from the plate, appears to be a variety of this.
Rhododendrons are more readily raised from seeds than persons unacquainted with the operation may imagine; the seed ripens about February; it is very minute, and should be sown immediately in pans or pots of very saudy peat or leaf mould; the seed had better not be covered, merely shaken over the surface of the soil, and the latter kept covered with a little damp moss, until the seeds are up and in their seed leaf, when it should be removed; the seedlings must, however, be kept shaded. I ought to have said when sown, the pots should be placed in a gentle hotbed or propagating house, where the atmosphere is close, humid, but not very hot; they had better for the first year be grown in a honse of this kind. By the first autumn they ought to be three to four, and many six inches high. The first winter they will require shelter in a close frame or pit; all hardy varieties, such as Catawbiense, maxima, Ac, can be planted out in spring in prepared beds of peat or leaf mould, etc, in a shady situation; in about two or three years they will commence flowering, though many will not for three or four, and some later.
In a climate such as that of England, these plants may be cultivated in open exposed situations; but in such a situation here these plants would suffer under our brilliant suns, their natural habitats being the shade of forests. Under the shade of trees will therefore be found their proper place. These beds or masses may be formed eighteen inches deep, and any given width, and filled with sandy peat, or leaf mould. As the former is not often to be had, the latter will answer every purpose; with it may be mixed a good quantity of sawdust, either in a fresh or decomposed state. This last has been found one of the best materials to mix with rhododendron soils; the small fibres will root freely into it, even in a fresh state; this may appear strange to some, yet it is nevertheless true, and I would strongly recommend it to persons forming rhododendron beds. Those who have them made already will find a mulching of sawdust over their beds three or four inches thick, of great advantage.
*Mr. H. Burn, of Tottinghsm Park, England, began to hydridize about the same time. Fifteen years ago, on visiting Tottingham Park, Mr. B. pointed out a large plant of R. Catawbiense, from which he raised the bulk of his seedlings. It was at the time growing with his other rhododendrons out-doors, but he remarked he was in the habit of putting it in a tub early in spring, and force it that he might have it in bloom the same time as arborea.
† I am aware it has been said these may be purchased much lower; but these are mixed seedlings. A few years since a large lot came to this city from one of the most noted firms in England; they should have been Catawbiense and maxima, chiefly the former, but one-tenth did not belong to these varieties; the consequence is, that sun and frost have nearly destroyed the whole.
In planting trees and shrubs the universal rule is, plant no deeper than they stood before. Though good advice for trees in general, it will not hold good for rhododendrons.; on the contrary, I would recommend having them planted three or four inches deeper than they stood before; this is the practice of the best growers. I shall probably be required to give a reason for this; I would say it arises from the fact that their roots are mere fibres or threads, and they are disposed to produce them from the stems when planted deep or mulched over. If observed in their native habitats, it will be found that there is almost invariably a quantity of decayed leaves and half decayed, congregated about the stems to a considerable height; hence the good effects of planting deep or mulching high.
[" Mulching high" will answer alone; the best success will be had by those who plant near the surface, in fact only sift leaf mould and sand on the roots, staking them, and letting nature have the same process she loves in the native place of these lovely plants. - Ed.].*