Our odd piece of Connecticut countryside is shaped rather like the blade of a paring knife. We cleared the point to make a wild-flower garden. At the blunt end, on one side, a tree-lined bank dips down to the road. On the other, there is an old, low rock wall that’s not particularly beautiful, nor is it suitable for dry-wall planting. When we finally whipped the central lawn into shape, we realized that a flowering border would be nice against the wall—a low, narrow border with colorful bloom all summer long.
To be in proportion and harmony with the setting, the border had to be completely in miniature—following accepted principles for selecting and arranging plants, but executed in small scale. Finding the proper plants has been a challenge; arranging them has been a trial-and-error proposition, because many varieties are entirely new to us. But last summer, the little border began to look the way we had visualized it—taller specimens in the background, ground-hugging cushions facing them down in front, small groups of straight spires for accent at strategic intervals. It will probably take another season or two to perfect the blending and contrast of flowers and foliage, and to get the most colorful and constant succession of bloom.
This is not, of course, our first acquaintance with miniature perennials; and it couldn’t possibly be our last. They combine beautifully with small shrubs, show off to advantage in small rock gardens, add an artistic finishing touch to garden pools, birdbaths, and other ornaments. They’re at their very best in outdoor planters and raised beds on patios and terraces, and in ribbon edgings along walks and walls.
Although they’re precious in flower, many varieties—candytuft, lavender, sempervivum, thyme, plumbago, to name a few—are equally decorative without bloom. This is a valued advantage when planting space is limited. Gardeners with limited time use perennials lavishly because, once established, they’re mostly permanent, and they require a minimum of care. Somehow, I sympathize with a writer who found more pleasure in spring’s tufts of fresh new growth than in the full bloom of summer. Nostalgically, one welcomes the return of an old friend; practically, one knows it will tend to its business of growing and flowering with very little personal attention.
This leads us to the question, “How perennial is a perennial?” and to the obvious answer, “It depends....” To begin with, it should live at least three years in your garden. After that, some varieties need to be lifted and divided into smaller plants with fresh new vigor; some may need to be replaced completely; some few may grow on indefinitely without renewal, or may replace themselves with seedlings that are often of doubtful value.
In the language of the catalogues, a “hardy” perennial is one that can withstand fairly severe winter cold, and may not be hardy in Southern gardens where it is not frozen into dormancy. Most hardy perennials are “herbaceous”—the stems usually die back to the ground each winter; some few have stems that may or may not be somewhat woody and persistent. A “tender” perennial is likely to be killed by cold weather, and is grown as an annual in the North, if it is grown at all.
The life cycle of a biennial extends over two years. It is grown from seed, may or may not need special protection to carry it over a cold winter, produces flowers and seeds the second year, then dies. Some biennials sow themselves with such faithfulness they’re regarded as perennial. The comparatively few biennials among flowering plants are grown much like perennials; miniature varieties are covered in this chapter.
Originally, I was firmly resolved to admit as miniatures only those perennials that grow less than eight inches high. But I couldn’t resist stretching the limits an inch or so to allow for a ten-inch flower stem above a small, flat rosette of leaves; and I found that the height limitation allowed free entry to some rambunctious spreaders that could quickly ruin a miniature garden. So I finally settled on biennials and perennials that are miniature in general appearance and habit, without strict measurements, and with flowers and foliage in suitable proportion for miniature gardens.
For the first year or so, locating some of the small perennials we wanted was rather like a treasure hunt; we never knew where we’d find a clue. Occasionally, we’d spy a prize on a visit to a local nursery. Frequently an advertisement or a tip from another gardener would give us the name of a promising mail-order supplier. Those who specialized in rock-garden plants proved to be particularly fruitful prospects. Often, we started our plants from seeds and discovered later that mature plants were available, had we known it. Now, we have quite a list of sources for miniature perennials which we happily share with you, beginning on page [259].
In selecting suitable varieties, decorative effect is naturally the first consideration—size, habit, and blooming season; color and texture of flowers and foliage; how the plants fit into your design and planting plan. Equally important is hardiness; not only ability to survive a cold winter, but also adaptability to other climatic conditions. Some perennials simply will not grow where summers are hot and dry; others will live but can’t mature enough to flower where nights are cool or growing seasons are short.