In considering the part played in modern gardens by shrubs and trees we might first take the early bloom of certain standard flowering trees, such as Plums, Almonds, Cherries, and various Pyruses. It is to be remembered that this comes as early as April. A little later we have the Thorns, then the Robinias, the Catalpas, and many others.
The spring-flowering trees allied to the great domestic fruit genera are beautiful in a very young state; they grow slowly and they never attain to great proportions. It follows, therefore, that they are suitable for small, as well as for large, gardens. No garden-maker can afford to overlook them. He may have at the bottom of his heart a particular love for some special flower; he may have within himself the makings of a narrow specialist in Carnations, Roses, Dahlias, or Sweet Peas; but if his garden is to be a garden at all, it must have some permanent features.
The amateur should not permit himself to be prejudiced against the spring trees because they are artificially propagated by budding or grafting on tall standard stocks of Crab, Gean, Thorn, or Plum. This, indeed, gives them their instant value, for it lifts them at once on to a conspicuous plane, and permits of their being associated with beautiful bushes, which hide the bare stems of the standards and in no way interfere with the spreading heads.
The flowering trees are a glorious feature of the garden in spring. It may be that they are ornamental with fruit or berry in the autumn, but be that as it may, their spring charm amply justifies their existence. They rarely fail to bloom, and generally they clothe their branches in flowers from base to tip. They are not long-lasting, but they serve their purpose, opening the garden year with a flush of beauty. It is not necessary to plant them thickly. A few trees here and there, or spaced in shrub borders, will give a touch of warmth, life and colour at a time when the cuckoo begins her call.
Timber trees will be planted sparingly in small gardens, and he who is tempted by dreams of coolness and shade will do well to remember that he can get these agreeable features without introducing coarse and greedy trees such as the Elm and Poplar. He may think of the Copper Beech, the Mulberry, the Catalpa, the Tulip Tree, ornamental species of Oak, and others which are described in their proper chapters. There are, of course, many places in which garden melts into park and woodland; and here the trees of the forest will have their appropriate place. This question of tree-planting presents, perhaps, as nice a problem as any which besets the garden-maker. He has to think not only of the benign influences of dew and shade, but of the maleficent effects of drip and root-foraging. A balance has to be struck. Isolated lawn trees cannot be planted with as little consideration as belts of Larch. Trees for the inner garden, for the house-confines, must be kinds which do not send out locust-like plagues of root, nor grow stiffly, but which have graceful habit and ornamental foliage. One often sees heavy belts of cabbagy trees quite close to the walls of a house, where there is inadequate perspective. These are cases in which the same mistake has been made as is made by the small gardener with his Laurels. A belt of trees has been planted for shelter, without thought as to their ultimate dimensions. The trees have grown, thinning has been neglected, and presently a gloomy mass is formed.
There can be no doubt that a new garden requires constant observation for several years in order to maintain its balance. This is not least the case with gardens which have been formed under the supervision of a competent landscape gardener. He is bound to give an immediate effect, and he cannot do that without leaving some thinning and rearrangement to be done afterwards. A shrubbery must be either painfully thin in its youth or gorged in its maturity that is to need no manipulation during its adolescence.
When the flowering and the large foliage trees have been considered there remain two great classes: the flowering shrubs and the coniferous trees. The part of the former is growing yearly in importance. It is to this class that the greatest additions have been made in modern times. Many entirely new shrubs have been brought from China, and while exploration has been going on in the Far East hybridizers have been at work at home, so that novelties have come from two entirely distinct sources.
If flowering shrubs were planted at all in the old days it was in the form of groups of Rhododendrons, which were generally set on the outskirts of lawns. It was rare to see beds or broad belts of various kinds of flowering shrubs, associated harmoniously. That, however, we are beginning to see now, and what we may expect to see more and more frequently as the years pass. Lovers of herbaceous plants mix their favourites with greater or less skill in borders, and just as they do this, so will shrub-lovers make borders of the plants which they like best. It is often the ideal way of growing a shrub to mass it in a bed to itself, but owners of small gardens cannot do this to any extent, and so they will put the kinds together in beds, borders or belts.
Does a comparison between shrub-borders and herbaceous-borders suggest itself? Such a thing is pardonable. The shrub-lover can point to permanent effect. He is able to claim superiority in the fact that his areas are never bare, nay more, that by a judicious use of evergreens, or such deciduous shrubs as have coloured stems, he can have winter as well as summer beauty. Nor can it be said that the balance is redressed by superior brilliance in the summer. No herbaceous plants are gayer than Weigelas.
It is probable that as time passes, and more and more beautiful shrubs are introduced, there will be a growing tendency to form shrub-borders. Not a few amateurs, enamoured of the new shrubs, but reluctant to give up herbaceous plants, will try to form joint borders. With care and restraint success is not impossible.
The less hardy shrubs will find appropriate places on or under the lee of walls. Many beautiful kinds that are in danger in the open are safe on walls, where it is easy to fix a mat or other shelter over them in severe weather.
The conifers present a striking contrast with the foregoing classes. For the most part they are distinguished by dense habit and small leaves. Viewing them broadly, we consider them as dense, evergreen, columnar or pyramidal trees, in no sense brilliant or showy; but with a refined and "well-bred" air, which renders them admirable isolated objects in selected parts of the garden.
With so much ground to cover in a not inadequate but still limited space, this survey of the part played by shrubs and trees in modern gardens must necessarily be brief. We see, however, that while giving that play of light and shade, that suggestion of cool and dewy peace, which forms so great a charm of the garden, they do far more, giving us colour beauty from the first days of spring, exquisite tints of leaf and stem throughout the year, brilliant fruits and berries and graceful and elegant habit.