REASONS FOR THE MAIN FEATURES OF THE PLAN. In endeavouring to accommodate the design submitted to Mr. Strutt to his instructions and to the situation, the first point determined on was, that the whole interest of the garden should be contained within itself. The mode of doing this was next to be considered; when it appeared that a general botanic garden would be too expensive, both to create and to keep up; that a mere composition of trees and shrubs with turf, in the manner of a common pleasure-ground, would become insipid after being seen two or three times; and, in short, that the most suitable kind of public garden, for all the circumstances included in the above data, was an arboretum, or collection of trees and shrubs, foreign and indigenous, which would endure the open air in the climate of Derby, with the names placed to each. Such a collection will have all the ordinary beauties of a pleasure-ground viewed as a whole; and yet, from no tree or shrub occurring twice in the whole collection, and from the name of every tree and shrub being placed against it, an inducement is held out for those who walk in the garden to take an interest in the name and history of each species, its uses in this country or in other countries, its appearance at different seasons of the year, and the various association connected with it. A similar interest might, no doubt, have been created by a collection of herbaceous plants; but this collection, to be effective in such a space of ground, must have amounted to at least 5000 species; and to form such a collection, and keep it up, would have been much more expensive than forming the most complete collection of trees and shrubs that can at present be made in Britain. It is further to be observed respecting a collection of herbaceous plants, that it would have presented no beauty or interest whatever during the winter season; whereas, among trees and shrubs, there are all the evergreen kinds, which are more beautiful in winter than in summer; while the deciduous kinds, at that season, show an endless variety in the ramification of their branches and spray, the colour of their bark, and the colour and form of their buds. Add also, that trees and shrubs, and especially evergreens, give shelter and encouragement to singing birds, to which herbaceous plants offer little or no shelter or food. There are yet other arguments in favour of trees and shrubs for a gardens of recreation, which are worth notice. Herbaceous plants are low, small, and to have any effect must be numerous; while, to acquire their names, and look into their beauties, persons walking in the garden must stand still, and stoop down, which, when repeated several times, would soon, instead of a recreation, become very fatiguing. Now trees and shrubs are large objects, and there is scarcely one of them the beauty of which may not be seen and enjoyed by the spectator while he is walking past it, and without standing still at all. A herbaceous plant is chiefly interesting for its flowers, and the form of its foliage, in which in general there is little change of colour; but, to these two sources of interest, trees and shrubs add the opening buds in spring, the colour of the unexpanded foliage immediately after it has burst from the bud, the fine green tinged with some other colour which the first leaves assume when they are fully expanded, and which continues more or less till the middle of June; the intensely deep green of summer, which continues till the end of July; the first changes of autumn to red or yellow, which commence in August; and the dying off of all the different shades of red, crimson, yellow, orange, brown, and purple, which continues taking place till Christmas; while some deciduous trees, such as the beech and hornbeam, the common oak in certain soils kept moist, and the Quercus Tauzin in all soils and situations, retain their leaves, after they have become brown, till the following May. There are also, in deciduous trees, the colour and bloom of the young shoots of the current year; the different colour which the bark of these shoots in many cases assumes the year following (Salix decipiens, for example); and the colour and texture of the older shoots, and of the branches and trunk. In addition to these sources of interest, there is a very great beauty in trees, which, from the improper planting of artificial plantations, is often overlooked, or rather concealed; and that is, the ramification of the main surface roots at the point where they join the trunk. In general, trees are planted so deep that this ramification never appears above the surface, and the trunk of the tree seems fixed in the ground like a post which had been driven into it; an appearance as contrary to truth and nature, and also to the health of the tree, as the shaft of a column without a base or a capital would, if employed in a building, be to architectural taste. To prevent this monstrous and unnatural appearance from occurring in the Derby Arboretum, I have directed all the trees to be planted on little hills, the width of the base being three times the height of the hill, so that the junction of the main roots with the base of the trunk will appear above ground. Much more might be said to justify the preference which I have given to an arboretum over every other kind of arrangement for the Derby Garden, but I consider any farther remarks on the subject unnecessary.
