Several principles that have guided the formal garden designs of palaces and grand manor houses take on new interest when applied to smaller gardening spaces. Symmetry brings visual order and balance to even a modest garden. The repetition of forms typical of a formal garden organizes both plants and their viewer. As simple a pattern as a line of pots identical in size, shape and color along a fence brings a formality and restfulness to a small herb and vegetable garden.
The goal of a prim garden is subtlety rather than drama, the crispness of a gingham check as opposed to the drama of a neon plaid. Dramatic shapes (Alocasia elephant ears); size (the hyper-energetic Ricinis communis, or castor bean); and configuration (billowing, trailing or just madly all over the place -- any plant name ending in contortus, grandi, procumbens or plumosus for starters) are all candidates for planting outside the prim garden.
The absence of dinnerplate dahlias, frothing wisteria and massed cannas leaves space in the prim garden for flowering plants that fade into the background of their more dramatic cousins. As a companion to dwarf evergreens and mound-shaped creeping phlox, creamy or pale pink Impatiens walleriana makes a previously unnoticed floral display. One or more varieties of the dead-nettle ground cover Lamium maculatum, "Pink Pewter," "Lemon Frost" or "Silver Beacon," combines small-scale leaf and blossom interest. Overlooked annuals like ageratum or Begonia semperflorence cease to be filler-plants and contribute modest -- prim -- seasonal accents.
The key to formal gardens of any kind is frequent maintenance, both to keep plants within desired sizes and to avoid the visual disruption of major change. Change will occur in a prim landscape, as in any other, but seasonal upheaval is kept to a minimum: A mixture of well-trimmed perennial and annual herbs provides some remaining cover for harvesting of annuals, for example. Evergreens such as dwarf arborvitae and boxwood remain constant, while annuals along their borders may change, spring through fall. Frequent minor trimming, meticulous weeding and the continuity of a single-color mulch support the formal tranquility of a prim garden plan.