Pleasure gardens are divided into two classes according to whether their emphasis is architectural or horticultural. In the architectural class the individual interest of the plant material which is used to achieve the design is of secondary importance. The plants are arranged and selected solely with regard to their size, form, color, and scale. This allows a vast latitude, for shapes desired in the design may be represented by any one of half a dozen quite different species. In fact, plants are here used rather as architectural members than as anything else. The architecture of the buildings and other accessories should predominate, but the architectural appearance must extend to the planting also if the garden scheme is to be successful. Therefore the planting must have somewhat the same stiffness and rigidity as is inherent in stone, brick, or wood in so far as the material employed permits.


Figure 58. TOPIARY WORK.

An architectural garden should possess the same characteristics as a more extended architectural planting, but may be more fancifully treated and more highly specialized. A very interesting example of the use of architectural features in a decorative fashion is seen in the little "temples" which occur at the middle of the side retaining-walls of the formal entrance court at Montacute House (Fig. 57). The piers of the balustrade are crowned by stone pyramids, and in order to provide some contrast of elaboration with simplicity, and of curved with straight lines, these little circular buildings were introduced to emphasize the ends of a secondary axis.* The designer of a scheme of this sort may say to a horticulturist, "At this position I wish a tree or shrub of such a height, form, color, and texture," and he can safely leave it to the horticulturist to determine the species, knowing that the result will be successful so long as the specifications are followed. In such gardens plants are used to furnish backgrounds, to form part of an architectural mass, or, as in French and Japanese examples, they may even be clipped to carry out the details and forms of a style. Topiary work is not essential to the formal garden, but is often found in connection with it, and, indeed, would be out of place in any other kind of garden, unless only a single specimen were used. Topiary (Fig. 58) is not of sufficient importance in general landscape work to permit of discussion here.

In the horticultural pleasure garden the interest of the owner centers upon the plant itself, and the entire arrangement of the garden has as its one object the tasteful and advantageous display of the plants composing it. The masses of planting are arranged either as individual plants or as plant masses setting off the forms of the plants which compose them rather than designed to harmonize with any extraneous features. If there are any architectural elements, they should appear incidental. The season at which the garden is to appear at its best is a potent factor, and the harmony of leaf and flower, as well as the sizes of the plants, must be carefully considered.

* See pages 80-82.

Since the question of garden design is as important to the landscape-gardener as to the architect, some mention of the subject from the point of view of each should be given here. It is of course impossible in a limited space to deal in an exhaustive way with a subject as large as garden design.

Design and the relation of each particular type of design to special problems will form the briefs of this discussion. The particular plants to be used and the matter of architectural details and construction, not being essential design requirements, need not be considered at the outset.

After the preliminary scheme of a garden design has been determined upon, the architect can design special architectural features, and the landscape-gardener should work out the problem of plant materials. The question of architectural or horticultural emphasis must be decided by the conditions of the problem and its needs, without discussion as to whether the garden should be in the formal or informal style. The style must conform to the problem; the problem should not be arbitrarily squeezed into a style.

It has long been known that the old gardens of Europe were executed with certain broad principles in view, and that they were not laid out by men on the grounds without plans, but were carefully designed, with elaborate drawings, and then built at an enormous cost. A typical example of such a garden is the Villa d'Este (Fig. 59).

In the early Roman gardens plant material, on account of the climatic conditions, was a secondary consideration, but the plant material in a modern garden of the English type should be of primary importance for the same reason. On account of the general moisture and even temperature, it is possible to grow a great variety of plants in England, while the excessive dryness and heat of Italy prevent the use of any but the most hardy specimens. In these examples the style was primarily dictated by the climate. Almost any sort of climate may be found in America, and consequently the limitations and restrictions imposed by locality, being rigorous, must receive careful attention. A comparison of New England, New Orleans, and Southern Californian conditions will illustrate climatic differences. New England winters are long and cold, with a late spring and an early autumn. Therefore only plants which are hardy enough to live through severe weather and require only a short time for flowering and fruition are suitable for use.