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.
We have long known, and ere this spoken, of the great merit of some new hybrids and varieties of Clematis recently raised, but we had no sufficient idea of their capabilities till we visited the nurseries of the raisers, Messrs. Jackman, of Woking, in the early part of this month. The Clematis is a well-known genus, often very pretty, from exhibiting a multitude of small flowers, like C. campaniflora; often showy, from a profusion of handsome ones, like C. montana; and frequently rampant, like the common Traveler's Joy; but it is only of late that it has become magnificent, or, rather, that its magnificence has been rendered available for flower-garden ornamentation and general use. There has long been a splendid species of Clematis (lanuginosa) in cultivation, with flowers of noble proportions, often six, seven, and eight inches in diameter. This, though finer as regards its size than any of the new ones, and having in addition to the normal blue form two exquisite snowy white varieties, was generally so slow to produce flowers, and leaves too, that it remained almost an unused plant. Hardy enough to do some good in nice positions, it was almost useless for general open-air culture.
But, fortunately, Mr. Jackman succeeded in crossing a very hardy free-growing species with this lanuginosa, and the result is a breed with the vigor of a common Clematis and the large and splendid flowers of the lanuginosa. But the color was also changed: rich purplish and plum hues were imparted to the pale lavender-blue or white of lanuginosa, and some of the richest hues of purple to be found in any flowers are now displayed by the varieties of this race, while one or two of the new kinds are of a fine soft blue or mauve, with stiff petals and handsome form. Not only are they distinguished by immense size and the richest color, but their profusion of bloom is something quite remarkable. Imagine a mass of foliage five feet high, supported on stakes, bearing flowers nearly as large as tea-saucers, and so profuse that their leaves are quite obscured. We have seen the plants shown in pots and in a cut state, but had no idea of their profuse way of blooming, and consequently of their great value, till we saw them at home, growing in various positions in the open air, and flourishing there as freely as British weeds could do.
They were arranged in various positions - planted in beds and pegged low down, like verbenas or ordinary bedding plants, or supported on stakes, up which they grew to a height of five feet or thereabouts, and then fell down in wreaths of the richest purple. However, few can have an idea of their beauty till they see them well grown. We believe them to be the noblest hardy hybrids that have been introduced for many years, and likely to effect much for the flower-garden, pleasure-ground, or rock-work. Being perfectly hardy, they are, of course, a great help in saving us from the perpetual expense for protection so much needed now. In fact, so satisfactory are they, that the only thing we have to settle about them is their position, and how they may be used most gracefully. Firstly, they will be of the highest value as purple bed-ding plants - our present colors in this way being poor indeed compared to these. They may be used effectively at about the same height, or a little higher, than the verbena; and near the earth, well pegged down in this way, they are less exposed to danger from storms, and enjoy a greater degree of heat.
Eventually, a beautiftil harmony may be presented by beds planted with them, if the various shades of purple, plum-color, etc., are associated in lines or circles; but it is needless to attempt the enumeration of the many ways in which-they will be found effective and beautiftil when associated with other good things. To pass from their use as bedding plants, we have next to consider them as the noblest obtainable ornaments for low walls, trellises, etc. To such they must, of course, be nailed or tied; and, once firmly fixed, if allowed to fall down in rich masses, so much the better. We, however, consider that the most simple and grand use of all to make of them would be to plant them on large rockwork, giving them a good depth of rich, light, and sandy earth, and allowing their shoots to fall over the face of the larger rocks without training, pruning, or any other attention whatever. Of course, almost the same words will apply to rustic banks, etc., with a warm exposure. For, drooping over the margin of those raised beds with edgings of wood or stones, they will look superb.
As to soil, it is important to note that they do best of all in a very sandy light one. They will not refuse to grow freely in any good soil, not too stiff; but we have always, observed them do famously in very sandy loam, and in any case in light stuff - deep as you like, however. Mulching the ground - or, in other words, covering it with an inch or two of loose, half-rotten manure during the summer - they like very much. It keeps the ground open and agreeably moist to the very surface. As to pruning, it is simply managed by cutting the plants back to within four or five inches of the ground in early spring - that is, if they are used for bedding, or in any way in which they may spread out low upon the ground. But when we wish to cover walls, etc., with them, the case is altered, and the stems may be allowed to go as high as they like, merely cutting them back and thinning them out a little. In banks, rockwork, etc., they might with advantage be left "to nature," no pruning, no attention being required after the first planting in good free soil. The best of the class of Clematises of which we speak, and it must not be confounded with any others, are C. Jackmanni and rubro-vio-lacea. Both these kinds are now cheap.
But since their appearance many new kinds have been raised, of which the best are Rubella, Prince of Wales, Lady Bovil, Thomas Moore, and Mrs. Bateman. - The Field.