New Orleans is warm the year around, with plenty of rain and moisture, giving a large range of plant material, and even permitting the use of some vegetation of a tropical character.
In Southern California the winter is mild, but there is a dry season extending from July to December; consequently the planting material must be such as will survive long periods of drought and require little water. If a plant is well suited for one of these three sets of conditions, it will often be impossible to employ it to advantage in either of the others.
In an analysis of garden design, every problem must be considered from two points of view: first, that of use; second, that of its esthetic value. The use is of primary importance, but a garden is generally designed for pleasure purposes, and so the appearance can hardly be termed secondary; a garden should give pleasure as well as comfort to the beholder.
The importance of the topographical features of the landscape as affecting garden design may again be noted in a comparison of the French and Italian gardens. The magnificent conceptions of Lenotre could never have been executed elsewhere than on a broad plain, nor can one conceive of such designs as those of the Villa d'Este and the Villa Lante as existing anywhere but on their own rocky hillsides. In fact, in each of these cases the garden owes its peculiar charm to an insistence upon the topographical surroundings and contours, and these, instead of being considered as limitations, have been of great assistance in determining the garden scheme.
Japanese gardens are often built upon uneven ground, because they generally represent the whole countryside, with hills and plains upon a very small scale. Informal gardens generally look better upon uneven ground, for it is difficult to make level ground appear naturally informal.
If the gardens are designed at some distance from the house, the character of the architecture will have nothing to do with the garden design, and the garden may be considered as an entirely separate feature. Gardens in connection with the house and treated as out-door rooms (Fig. 52) should be of the formal type, because their lines must harmonize with the architecture, and carry the idea of the building beyond the limits of brick and plaster. These may be called architectural gardens. It must be remembered that a formal garden does not necessarily mean clipped hedges; there is as wide a range of formal style as of informal.
The style may often become gradually more informal as the garden recedes from the house, and in this way may give a gradual transition from natural to artificial features.
In the horticultural gardens, where the main interest is in the plant material, the gardens may be either formal or informal; but the main determining factors are the kind of soil at hand and the species of plants which it is desirable to use. Of course the garden should be so designed as to display these to their best advantage. Topography likewise enters here in determining the amount of grading which will be necessitated by the type of garden required, and conversely in the adaptation of the garden style to the contour of the existing landscape.
The informal type of garden is not necessarily more nor less admirable than the formal type; it is, indeed, more often unintelligently used than the formal garden, and consequently is receiving a larger amount of meaningless praise. In fact, the sort of adulation that is often heaped upon the informal garden has done a great deal to injure it in the minds of those who believe that design has some value. It is unfortunate that it should have suffered in this way, for at its best it is altogether a desirable type of planting.
Figure 60. A GARDEN AT MILTON, MASS., ILLUSTRATING A GOOD USE OF BEDDING PLANTS.
In characterizing the architectural garden one might say that the planting materials are used merely for form and color, but principally for form, and that they may be considered almost as architectural members. Wherever flowers appear in a formal garden it is not on account of the individual beauty of the flower itself, but because a color note is needed to relieve an otherwise somber color scheme. In Figure 60 red geraniums are used for that purpose. The vases on the balustrade at the Villa Lante are an ingenious means of introducing plant form and color into very strictly architectural surroundings (Fig. 61).
The accent in the formal garden is generally a piece of sculpture or an architectural feature, such as a well-curb (Fig. 62), a fountainhead (Fig. 63), a gate, stairs (Fig. 64), a bridge, a sundial, or a retaining-wall (Fig. 65).
Where accents occur in informal planting they are as a rule horticultural, and rely upon some difference in the accent plants from their surroundings. The difference may be in form, color, quality, or size.
Figure 61. ARCHITECTURAL VASES USED TO INTRODUCE PLANT COLOR, VILLA LANTE, BAGNAIA, ITALY.
As has been said, the horticultural garden is divided into three classes, according to its practical uses: the cut-flower, the vegetable, and the fruit garden. It is not necessary, of course, that these be ugly, but because designed entirely for economic purposes the gardens will necessarily appear much simpler and more monotonous than if they had been laid out with some emphasis upon their esthetic side.
Figure 62. FOUNTAIN AT VILLA BORGHESE, ROME.