ARBORICULTURE 310 The COMMON HORSE CHESTNUT (sEsculus Hippocastanum, L.), cultivated in Europe since the 16th century, 13 an ornamental tree of quick growth in good soil. Its hand some blossom surpasses that of all other British trees, and its massive foliage is effective, but the timber is of an inferior quality, only used for boarding and packing-cases, linings of carts, and wheel-barrows. It is rarely planted in mixed plantations where profit is an object ; it interferes with its neighbours, and occupies too much room. It is generally introduced near mansion-houses for ornament and shade, and the celebrated avenues at Richmond and Bushy Park are at the time of flowering objects of great beauty. From the crop of nuts which ripen in October seedlings are easily raised, and should be placed in rich loam, and transplanted before being finally planted out. ROADSIDE TREES AND HEDGES. Little attention is paid to the planting of trees along road sides, and in such situations healthy or well-shaped ones are seldom seen. A pit should be made of sufficient size (2 to 3 feet square), and filled with good soil mixed with rot ten dung. The plants require to be fenced, and for the first summer occasionally watered, and the earth dug and kept clear of weeds. In forming avenues on boulevards, tho trees should be planted 30 feet apart, and if space allows of it, there should be a double row to form a shady arch for pedestrians. The oversight of these is sometimes given to the surfaceman, or to a man appointed for the purpose, and it should be his duty to maintain the avenues complete. Trees, especially in or near large towns, are sub ject to injuries which disfigure their appearance or retard their growth, and not unfrequently destroy the plants. To prevent this it is customaiy to surround the stem with a cradle, or matting, or thorny branches. Hedge-plants are of great importance both for shelter and protection of plantations. By far the best for outside hedges are the common hawthorn and the wild crab. The sloe or black thorn makes an excellent hedge; but it throws up many suckers, and requires constant attention to keep it within bounds. It forms, however, an excellent barrier for picturesque plantations, where it is allowed to spread itself in every direction. Holly and yew hedges are suitable for inner enclosures. The holly forms an excellent hedge, both for gardens and fields, as its leaves are rarely injured by insects ; and, being an evergreen, it harbours neither weeds nor vermin at its roots. Birds are also much less apt to build in it than in deciduous hedges. It has two disadvantages, viz., the slowness of its growth, and imperviousness to wind in the winter season. Were holly hedges occasionally introduced among those of the common thorn, they would add greatly to the beauty of tho country in winter. The common furze sown on the top of a bank forms an effective hedge in a short period, but it is not durable. In moist soils, willows or poplars, and in situations exposed to the sea-breeze the elder, may be planted ; but such hedges can be hardly considered as fences from want of compactness and density of foliage. The land for hedges should be carefully prepared and freed from weeds before planting, and the expense of doing this will be well repaid by the growth of the hedge afterwards. The ground should be cleared of weeds two or three times a year until the plants have reached some height. Hedge plants should not bo pruned till after three years, or they will become stunted ; after that pruning should take place once a year. A hedge one-third beech and two-thirds haw thorn is excellent for high and cold situations. COPPICE. Coppice or Copso consists of self-sown or planted trees periodically cut before they attain the size of timber. This system of wood cropping was more extensively adopted thirty years ago than it is now, as the value of oak bark is much reduced owing to the introduction of foreign bark and other substances for tanning. One requisite for copse woods is that they should spring up freely from the cut root. Most of the broad-leaved trees and shrubs may be cultivated as coppice wood ; in soft, wet soils, birch, alder, and various willows are amongst the most useful trees, and in drier soils the oak, chestnut, and ash are valuable for this mode of cultivation. ORNAMENTAL TREES AND SHRUBS. As already observed, we exclude from consideration in this article flowering and fruit-bearing trees and shrubs. We also exclude all those that require special, protection, and confine ourselves to trees and shrubs considered orna mental from their general form, and suited for introduction into plantations in most parts of Britain. These are arranged under the heads of evergreen and deciduous. Evergreen Ornamental Trees and Shrubs. The climate of Britain enables us to cultivate many evergreens ; new species are imported, and varieties are produced by accident or experiment, so that the number is always increasing. All the pine tribe may be described as highly ornamental, and many of them endure the open air in the coldest parts of Britain. The Deodar (Cedrus Deodara] naturally grows in compact forests, clearing itself of side branches like the larch ; in this country single specimens have been exten sively planted of late years for ornament. Large quantities of seeds are annually imported from the Himalaya, and it is also raised from cuttings. The Lebanon and Atlas cedars (Cedrus Libani and atlantica) are closely allied to the Deodar ; and it is proved by Hooker that they cannot be separated by constant specific characters. The Atlas cedar is distinguished by a stiff erect leader, and the foliage is generally dark, that of the Deodar being light or bluish green. Cryptomeria japonica, the Japan cedar, is a beauti ful evergreen tree, attaining 100 feet in height, with a pyramidal head ; it yields cones abundantly. /Sequoia gigantea, the Wellingtonia or mammoth tree, remarkable as the loftiest tree known, attains 300 to 330 feet in height, and 80 to 100 feet in girth, and is a handsome and sym metrical tree. S. sempervirens, the redwood of California, is another giant tree, though of smaller size. Both species are hardy in England, and are easily raised from cuttings. 1 The Weymouth pine (Pinus Strobus) is a hardy ornamental tree, introduced in 1705, suited for cold situations; and still more so is the Pinus Cembra, which is of slow and erect growth and long retains the beauty of youth. Pinus excelsa is a hardy and ornamental species, from the Hima laya ; but when exposed to wind it does not thrive. It is inclined to seed rather too early and freely in this country. Some of the Californian and British Columbian pines are hardy and ornamental, particularly P. j)onderosa, the heavy wooded pine ; but it is easily blown over by the wind. Other species are P. Sabiniana, inops, and Murrayana. The Douglas fir (Abies Douglasii, Lindl.) is a handsome tree, as hardy as the common spruce, differing in the dark green colour, and apparently intermediate between the common spruce and the silver fir. It was introduced in 1827, and is of very rapid growth in England and Scotland. At Dropmore there is a tree which, at the age of 44 years, was 100 ft. high, with 9 ft. 7 in. girth at 3 feet above the ground. Many specimens in Perthshire raised from layers and cuttings since 1846, are 50 to 70 feet high. The - An interesting paper " On the WcUingtonia gigantea," containing a table of the growth of this tree on various soils in different parts of Britain, by Mr Hutchison, is published in the Trans. High. 5oc. oj
Scot. 1873.