This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
It is a very common practice in planting trees in park and woodland to dig a hole about two feet square, and a foot or eighteen inches deep, and in planting the trees the spits taken out are often imperfectly broken up. On light, friable, well-drained land this method may answer very well; but on a stiff clayey loam the holes should be larger, for two reasons: firstly, because in very wet weather a small hole is liable to become a basin of water; and secondly, because in very dry weather there is not sufficient broken soil to retain the moisture needed by the tree. A little extra labour in planting is never thrown away.
The practice of pruning and clipping shrubs into fantastic shapes happily belongs to a bygone time; the use of the knife and shears is now usually restricted to thinning out and removing odd branches of ornamental shrubs and trimming hedges. Where shrubs are pruned it should always be done with the knife, and in such a manner as to leave them with a natural appearance. Clean cutting is more agreeable to the eye, and less hurtful to the tree, as the wound readily heals over. Dead branches should be cut off neither too close to the main stem nor at a distance of several inches; if cut almost close to the bark of the stem or parent branch, and the tree be otherwise healthy, the wound will soon be grown over; but if at a distance, the bark cannot cover, and consequently decay often continues, and penetrates into the centre of the main branch or stem, ultimately causing its death.
Where under-drainage is necessary, or where sewage conduits are carried through a garden, they should be so contrived as to be as far away from the roots of trees as possible, or it eventually comes to the destruction of either drains or trees. It is not unusual to lay them by preference in the roads and walks, but this is not always practicable. Flange or socket pipes should be used to prevent as much as possible the intrusion of roots.
The operation of laying turf, though requiring comparatively little skill, is frequently badly performed owing to the prevalence of the erroneous impression that thick turves will succeed better than thin ones. The ground may be properly levelled with a sound, firm bottom, and a little crumb on the surface to receive the turves; but if they are cut too thick, and especially if dry weather set in, the result will be very unsatisfactory. A sod can scarcely be cut too thin, for the thinner it is the sooner the herbage will form new rootlets in the fresh soil. Besides, a thin sod is more elastic, will beat out, and cover more space than a thick one.
The cultivation of herbaceous plants calls for more skill and management than that of trees and shrubs, because there is a greater diversity in their habits, habitats and special requirements, and because they are more exposed to the vicissitudes of weather, and the attacks of insects and animals. And then the work in the flower garden proper has to be repeated year after year, and upon its skilful execution depends the amount of pleasure derived from this the most attractive part of the garden. Consequently we shall devote a special chapter to the explanation of the best methods of raising, treatment, and propagation of herbaceous plants, including also a few hints on the management of flowering and ornamental shrubs requiring special conditions.
We may here say a few words on the general propagation or multiplication of plants. There are two distinct modes of raising plants, namely, sexual, from seed; and asexual, which includes all the different methods of grafting, budding, layering, offsets, division, and also propagation by cuttings, etc. The most important means of propagation practised by gardeners on a small scale are from seeds, cuttings, and root-division. These three methods represent the raising of annual plants, and the multiplication of tender bedding plants and herbaceous plants respectively. Grafting, budding, layering, etc., are practised on a limited scale only, or not at all, by the small gardener or amateur, and, to a certain extent, more for recreation or experiments. But advantage should be taken of these means to increase the stock, or propagate rare varieties, where desirable. Otherwise these operations on an extended scale are restricted to nurserymen and florists. Budding is the method generally employed in the propagation of Roses, and variegated, double-flowered, weeping and other varieties of ornamental trees and shrubs. Usually some common or vigorous-growing species is selected for the stock upon which the rarer varieties are budded. For the Rose stock, clean stems of the common Dog-Rose; for weeping and other varieties of Ash, the common Ash; for various species of Cytisus and Genista, as well as improved varieties of Laburnum, the common Laburnum; and so on, always selecting a species of close affinity.
Of late there has been a tendency on the part of horticultural writers to depreciate this and that, till there is almost nothing left for the garden. One objects to variegated plants, another terms weeping trees abnormal and unnatural, whilst a third would exclude standard Rose-trees from the garden, to pay nothing of the difference of opinion regarding the different styles of flower-gardening. But this should not deter planters from employing these things in moderation, and in appropriate situations. An excess of variegated plants, or a garden full of standard Roses, should be avoided, as well as any other inconsistency; and few persons would think of forming a plantation of weeping trees, such as one occasionally sees in a burial ground.
It is unnecessary for us to describe the process of budding, as it is one of the first things to which a young hand takes a fancy; but we may caution the inexperienced to loosen the ligatures before they have injured the growing bark. The incision should not be made deeper than the bark, nor longer than the inserted bud. For standard Roses, the buds are better inserted in the lateral branches, as close to the main stem as possible, than in the main stem itself, as they form more equal-sided heads. Dwarf or bush Roses are either grafted, or budded, or on their own roots. Plants of the latter description are preferable, as there are no foreign suckers developed; but some varieties do not succeed so well on their own roots as they do when worked upon a more vigorous stock. The Rosa Manetti, a variety of unknown descent, is usually employed as a stock for dwarf Roses. Like most of the climbing Roses, it readily strikes root from cuttings in the open ground. Ornamental shrubs and trees are usually budded in the main stem of the stock, which should be cut off immediately above the inserted bud as soon as the latter has made a shoot from six inches to a foot long; and the shoot being trained upright will form a straight stem, and quickly overgrow the point of union. Weeping and some other trees grown as standards are worked on stems of convenient height, according to what is desired. The season for budding depends entirely upon the weather; but any time when the bark separates freely from the wood will answer. Roses, if budded during the first growth, frequently start, and even flower, the same season; but the buds of most other things remain dormant until the following spring.