The height of outer garden enclosures will vary according to the surroundings. Where the outlook is not particularly attractive they may be six or seven feet high. High walls are also a necessity in some localities as a protection to the plants. Where it is thought best to maintain views of the surrounding landscape a wall three to five feet high is sufficient. Subordinate garden walls should not be more than three to four feet high. On a small place, where the scene must be made within the enclosure, a high wall is necessary.
When walls are adopted as an enclosure for the garden they should always be of the same material as the house. If the house walls are stuccoed the sides of the garden wall should also be stuccoed, though, to provide a slight contrast, the piers and coping may be of brick. This refers to gardens which are adjacent to residences. When they are set apart, more or less isolated from the house, the material may differ from that in the building.
When walls of stone, brick, or stucco are used for the garden enclosures they should be designed along artistic lines and be in perfect harmony with the scene to be created.
Soft gray sandstone (Fig. 118) with an occasional marking of red and orange is the most pleasing stone for the enclosing walls. These should not be less than eighteen inches thick with a footing course to project six inches beyond on each side, making a thickness of thirty inches. The depth of the footing should not be less than eight inches. The depth of the foundation below the frost line will depend on the latitude. In Philadelphia and vicinity the foundation should extend to a depth of three feet.
Fig. 118. - The natural background on an adjoining property makes a good setting for the garden. Gray sandstone enclosing walls with similar coping stone. - See pages 133, 138, 140 149.
Stone walls with mortar joints should be less finished in texture than the house walls. The joints should be raked out to a depth of from two to three inches. The shadows produced by this treatment have a softening effect and the vines, extending their clinging tendrils into the interstices, seem to be more firmly fixed to the supporting structure.
The coping should be of stone similar to that in the body of the wall (Fig. 118), with a projection of two to three inches, according to the roughness of the face. This refers to a coping of stones laid flat. If the coping stones are set on edge they should be set flush with the sides of the wall. The coping should be level along the top.
The irregular or so-called scotched coping is not at all satisfactory for a garden enclosure, as it is a line of agitation and most unrestful.