In addition to vertical enclosures, there are horizontal overhead enclosures for you to consider. These may provide for either partial or complete overhead protection, through extensions of the house, independent structures, or overhanging foliage. There may be open structures of laths, trelliswork, or netting, or outdoor skylights with translucent materials such as canvas, plastics, or glass to give diffused light. These materials can be set in removable panels.
Trees with their branches overhead may be depended upon to provide shade, to cut off heat, and to reduce glare and sound. Since some trees are out of all proportion to the size of a place, be cautious in selecting the number and sizes of trees. Choose small trees for small places. A balance of light and shade should be sought.
Open and Semi-enclosed Structures
Pergolas, arbors, and lath houses are open-type structures, while garden houses, bathhouses, pavilions, and overlooks are semi-enclosed. You should think of both types in terms of their function and structure and their relation to space. They furnish overhead, or horizontal, as well as vertical, planes of enclosure.
Pergolas and arbors overarch walks, and may be used to lead to more substantial terminals of interest. They may be used as terminal features in themselves. As vine-supporting elements, they provide a basis for imaginative design. Such structures may be made entirely of wood or metal, or partly of wood and partly of brick, stone, or concrete. They may be quite rustic wooden structures, with bark retained or removed, or they may be made of planed wood such as redwood, Douglas fir, or cypress. Because of termites and fungi, wood supports need to be anchored in concrete. Supports, however, may be made of stone, laid up in cement mortar, with capstones of the same material.
Materials that are lighter than wood and just as strong, such as aluminum, which is rustproof, may be used. The strength and character of pergolas will depend upon the vines they are expected to support. Wistaria, for example, requires large, strong structures. When a solid roof is to be added, additional bracing will have to be provided.
Turf is not practicable for the floors of pergolas, because of the dense shade of the covering vines. Brick, slate, or stone floors are good for this purpose. Cement floors are the least desirable.
In the hot sun of southern California, many plants will not grow out of doors in the direct rays of the sun. Hence, the lath house is frequently used as a protective covering to cut down on the amount of direct sunlight. Such a structure usually has a pitched roof; its wood laths are spaced one lath apart on the vertical sides and the top. Or the top may be formed with alternating laths above and below the framework for more even lighting effects. Joists must be heavy enough to support hanging baskets of flowers, if desired. Glass panes can be used if protection is sought from rain, with slight overlaps of the panes; for such purpose, a well-framed structure is needed. When glass is used, roller shades of muslin or other material can be used to control the light.
The Garden House
The garden house can be a pleasant, semi-enclosed structure, located somewhat away from the house and connected to it by an arbor or a path, or it may stand at the corner of a terrace or in the corner of a walled garden. It can serve as a focus of special interest. It should be an integral part of the garden scheme.
Work and Storage Centers
In any garden there is often need for a work center. This can be located in almost any part of the garden. Adequate storage facilities can make garden work less laborious and much more agreeable, and can be made to fit in well with the overall scheme. Quite an assortment of materials may be stored in such a center, including tools needed in lawn upkeep, seed sowing, propagating, transplanting, and potting; fertilizers, soil conditioners, and pest eradicators may also be stored.
The work center can be simple, consisting merely of an L wall upon which things can be hung and within which things can be stored. Or it can be subdivided by enclosures of panels and fencing. The work center should include work bench, pot racks for plants, and easy-to-clean floor surfaces.