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Permanent Plant Planters

Like their indoor counterparts, permanent outdoor planters may be part of an architect's design for a new house or for remodeling an old one. They may be a landscape architect's device for improving or completing the garden picture, or the individual touch of the home and garden decorator. Planters are usually part of a patio, terrace, or garden. They may be sunk in slate, stone, or paved floors, or raised above the ground or floor level with walls of wood, brick, stone, or other building materials. And they may contain permanent, perennial woody or evergreen plants, transient annuals renewed or replaced at will, or a combination of both.

Since they are permanent in nature, if not always in planting, raised or sunken planters are designed to serve a definite decorative purpose - perhaps simply to provide planting space for a vine that will climb the house wall, or to edge and enclose a terrace, divide two garden or living areas, or even to make a city rooftop garden possible. Their plants, including vines, are chosen to carry out and complete the purpose.

Before filling these planters with soil mix, put a two- or three-inch layer of pebbles in the bottom to improve drainage. In large installations pipe off excess water in some way. Instead of putting plants directly into soil, you can fill planters with peat or some other moisture-holding medium, and sink pots to the rim. These plantings are easily renewed, refreshed, or rearranged.

Because they must hold heavy soil, raised beds should be of sturdiest construction, with extra bracing inside at the corners and joints just like building garden steps. Use heavier wood than for portable containers, and take all precautions against weathering and rot.

In severe climates winter freezing and thawing can heave soil and throw planter walls completely out of line, or even crumple them. Make sure the foundation is firm, level, and below the frost line. For extra strength, coat the inside of the planter generously with mortar, and finish it with waterproof paint if you plan to put in acid-loving plants. Like lime, mortar counteracts the acidity of soil. Protect adjacent wooden house or garden walls against rot with a nonpoisonous treatment.