This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
The handsome evergreen shrubs which constitute this group, are for the most part indigenous to China, Japan, Tartary, and Northern India. They were originally associated with the Thujas, of which they formed the second section, but are now separated into a distinct genus under the sectional name, by which they were distinguished from the American or Western species.
All the sorts in cultivation are found to grow freely in ordinary garden soils, but prefer a drier situation and a lighter soil than the Thujas; and though most of them are fully equal to the rigours of our winters in the open air, they succeed best where they are protected from the full force of violent winds.
The following species and varieties are among the most distinct and ornamental: -
Biota Orientalis (the Chinese Arborvitae), found wild in great abundance in mountainous districts in China and Japan, growing to heights of from 20 to 30 feet, was introduced into Britain about 1752.
With a general resemblance to the American Arborvitae, it is readily distinguished, not only by the peculiar form of its cones, but by its much more sharply conical, almost columnar, habit of growth; compact, erect branches, and dense flat branchlets.
The branchlets have a warm light green colour in summer, which, particularly if the plant is growing in an exposed situation, changes to a brownish tint on the approach of winter.
Ever since its introduction this beautiful shrub has been one of the most conspicuous and highly valued ornaments of our gardens and pleasure-grounds; and, notwithstanding the many brilliant acquisitions to the list of hardy Conifers during the last twenty years, it has even yet few rivals for real elegance and symmetry of form, and it is still, as it richly deserves to be, extensively planted in the most choice collections.
Though quite hardy and of free growth in most districts, the finest specimens are invariably found where the soil is a deep light loam, the land well drained, the situation airy but sheltered, and plenty of space allowed for each plant to develop its branches on every side.
Like many other plants of a wide geographical range, the Chinese Arborvitae is remarkably prolific in varieties, and among the finest and most distinct of these are the following: - Aurea, or, as it is popularly called, "Golden Globe," is so very different from the parent, that it is difficult at first sight to realise the fact that it is not itself a species, but a mere variety, originating from seed saved from Orientalis. This lovely dwarf shrub has an almost completely globular habit of growth, the branches so abundant and so dense as to suggest the idea of solidity. In spring and early summer the young branchlets have a most brilliant golden hue, gradually changing as they become matured to a light green; the effect of the plant as a single specimen on a small lawn, as a centre for a flower-garden figure, or in front of clumps of the larger-growing species, is striking in the extreme. Globosa, with the peculiar compact globular style of growth, but with light green instead of golden branchlets, is a fine companion plant to Aurea, with which it makes a pleasing contrast: Oompacta is a very elegant, sharply conical dwarf bush, with abundance of branches densely clothing the stem from the ground upwards: Elegantissima has the compact columnar form of the species, and in summer its green colour; it changes, however, in winter to a bright reddish brown, the young branchlets in spring being tipped with gold: Semper-aurescens is a new and very interesting form of Continental origin, resembling the preceding in general appearance, but with, a finer golden variegation, which it retains with more or less brilliancy all over the year; though as yet comparatively little known here, this pretty plant will doubtless soon be widely distributed: Freneloides or gracilis is another singularly beautiful and distinct variety, found first on mountains in Northern India, and, like the species, of an erect, com_ jjact habit of growth, but much more slender in all its parts; it is very distinct, quite hardy, and deservedly very popular: Pyramidal is is a distinct and handsome form, with more robust branches, denser branchlets, and a more compressed columnar style of growth than the species, and makes a superb lawn specimen.
Biota Filiformis Or Pendula (The Thread-Branched Arborvitae) is found wild in high mountain valleys in Japan, particularly on the Hakone range, forming a bush varying in height according to soil and situation from ten to twenty feet. From its handsome appearance, and freeness of growth, it is highly valued and extensively cultivated in Japan and all over China as an ornamental shrub.
It was first introduced into British gardens early in the present century, and, though very properly classed among hardy Conifers, it will only succeed in well-sheltered localities. A rich, deep, loamy soil, rather light than heavy, with the subsoil either naturally dry and porous, or thoroughly drained, is also an essential condition to its well-being, and must be supplied if a vigorous, healthy specimen is desired. In favourable circumstances this curious and interesting plant forms a straight-stemmed, bushy-headed shrub or miniature tree, with long whip-cord-like pendant branches, rather sparingly clothed with small scalt-like leaves clinging close to the stern; the branchlets are numerous, and are disposed in clusters at irregular intervals on the branches. In summer he branchlets are of a light green colour changing in winter to a dark brown.
As its name implies, this species is a native of Japan, "where it forms a bushy shrub rarely exceeding ten feet in height. It was first sent home to this country in 1860, and has proved itself to be quite hardy, and to grow freely under similar circumstances to Orientalis and its varieties, which it so much resembles that some have doubted its claim to rank as a distinct species. Whether a species or variety however, there can be no question of its being a great acquisition to our hardy Biotas, and of its worthiness of ' admission to the most choice collection of ornamental Conifers. In habit of growth it is more broadly conical than Orientalis, but equally dense, the branchlets more compressed and fan-like, and makes a neat symmetrical specimen plant.
This distinct and interesting plant originated some years ago in Meaux, in Trance, from whence it was distributed as a hybrid between the Arborvitse and Red Cedar. Its hybrid origin has been doubted by some of the highest authorities on suck subjects, and it is now generally believed to be a seminal sport from some of the Biotas. It is quite hardy in Britain, if planted in a sheltered situation, and forms an erect, somewhat dwarf, bushy shrub, with slender, slightly drooping branches, disposed irregularly, but very abundantly, upon the stem. In summer it is of a light, slightly glaucous-green colour, changing in winter to red, orreddish brown. It is a pretty plant for a shrubbery or small lawn.