There is very little difference between a tree and a shrub. One might almost say that there is no difference, since the distinction is purely one of size. When dealing with ornamental trees and, shrubs, however, the distinction most generally accepted is that a: tree is limited at the base to a single, from which branches radiate to make a “head,” either a standard head of the usual type grown in the little garden, or a more bushy head, in which the branches come from perhaps only 1 ft. or 18 in. above the soil level. A shrub, on the other hand, frequently has many sterns growing from the ground level, and is encouraged to make bushy growth from the ground upwards.
The picture here shows a Giant Redwood, believe it or not. Instyle, you would not know it has the capacity to become the largest living thing on the planet. So size does not define the difference between a tree and a shrub.
All the remarks made concerning the selection and planting of trees apply to shrubs, but there is this difference, that whereas the ornamental tree in a garden should be allowed freedom to develop andits natural characteristic form, the shrub in garden design is generally made to conform to the gardener’s wishes. It may be pruned to some formal outline, as is often done with specimens of box and bay. It may be pruned less formally, perhaps with the idea of producing more and berries, or just to restrict the growth to the situation. In any case, is one of the important features of shrub culture, and it is one of the points that most often seem a stumbling block to the inexperienced gardener.
The old idea of shrub culture was often limited to a “shrubbery,” in which all the shrubs were collected. Modern gardeners allow themselves greater freedom, and use shrubs in the borders with herbaceousand even with , in the rock garden, as lawn specimens, as a screen for the kitchen garden, as material or a mixed hedge, and so on.
In fact, shrubs are valued for their permanence and brilliance even more than are the herbaceous perennials. It is quite a common thing today to find a fairly small garden in which the borders are more than half filled with shrubs, the reason being that these plants are labour-saving. Beyond an occasional clean-up of the soil in autumn, and the use of the secateurs at the appropriate season, they demand little attention, and remain attractive all the year round.
The principle of a shrub border can be very simply outlined. It should be arranged so that there is a “skeleton’ of evergreen shrubs that will furnish the border in winter. There should also be a sufficiency of, with different sea-, sons of blooming, t give some special interest to ea month in the year As an example of this one might plant a border with the following twelve shrubs: fragrans (January) berberis bealel (February) hamamelis moll’ (March), forsyth. (April), lila (May), philadel phus (June) olearia (July hibiscus (August) tamarix (September), caryopteris (October), coto caster (berries November laurustinu (December).
Such a list could be repeated wt variations over and over again, for the arrangement of a shrub border never loses its interest to the keen gardener.
Shrubs in the mixed border should generally be of the rather compact growing type, that need little pruning, but this depends entirely on the size of the border. In a small border of 5 ft. wide daphne Mezereum,in variety, and veronicas of several kin would be suitable, with lavender, senecio Greyii and santoline add a variation of foliage. The planter will easily be able to work out schemes for himself from the lists that are given elsewhere, and will find plenty of satisfaction in this task.
So much depends on a variety of factors—amount of pruning, for instance, and the question of when such pruning can be done, as well as the questions of soil, foliage colour, habit of growth, flowering and berrying colours—that it is useless to plan a border without some knowledge of the site.
On the question of shrub pruning in general a few hints may be given in summarized form.
1. The reasons for pruning shrubs are varied. Weto restrict the growth to the amount of space available in the border, or to let more light and air to the remaining branches so that the season’s new growth ripens and becomes “ woody “ instead of soft and sappy. Ripening the wood makes it less likely to be killed back by winter frosts, and more likely to develop flower buds for next season’s flowers. We prune also to remove dying branches and , and so obviate the risk of disease, and to remove damaged wood, through which both disease spores and insect pests frequently enter.
2.to restrict the growth of a shrub can be carried out at any time, but preferably shortly before a new season’s growth is due to begin, as the shrub will then recover more rapidly. Pruning hard back in autumn means usually that the shrub will remain bare all winter, or if new growth should break Out just before the cold. Weather, it will be too tender to stand the frost, and a blackened seared look will result.
3. Pruning for the sake of better flowers is timed so that the new growth coming from the remaining parts of the shrub will have as long a season, of growth as possible prior to flowering time. Thus the shrubs that flower on stems which grow newly each season are pruned in early spring, leaving just sufficient dormantbuds to develop into the desired strong stems and finally to carry the season’s flowers in late summer. Shrubs that flower on wood of the previous season’s growth are pruned hard back immediately each flowering season passes, as the new long stems have then time to grow and become well developed and ripened before the winter.
A few shrubs that flower like fruit trees on short old spurs, close to the main stems, are regularly pinched back, like the trained fruits, to induce the formation of these fruiting spurs. Very often, however, shrubs of this character are best left to their own devices, and should not be as strictly pruned as the others.