Add pizzazz with rock gardens

By Libby James
North Forty News

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For rock lovers with an overgrown collection or gardeners who must remove stony impediments before they can plant, a rock garden can be an attractive solution.

Low-maintenance and easy to get started, rock gardens can be installed almost anywhere and add a whole new dimension to the flatness and symmetry of a traditional grassy area or garden bed.

According to gardener Kelly Neal, who has a particular affinity for stone walls, gardening with and around rocks offers lots of opportunity for creativity. Her walls have nooks and crevices overflowing with small succulents and flowing tendrils of plants like creeping phlox.

Existing rock walls, patios and walkways can be transformed by tucking tiny plants into open areas. A raised bed or berm can become a beauty spot – large or small – filled with a variety of rocks and plants that require very little fertilizer and water and provide visual pleasure year after year. Many rock garden plants such as lavender, thyme and other aromatic herbs originated in dry, rocky areas and stay healthier and live longer with minimal water and fertilizer.

Neal encourages irregularity in a rock garden, to emphasize a natural look that grows from randomness in the shape, size and color of rocks and plants. Depending on space and terrain available, a rock garden can have a water feature or a birdbath, make use of a single special rock for a focal point, be devoted to the profusion of a favorite plant, or even be created in clustered containers.

Would-be rock gardeners need to first identify an area and determine the amount of sun and shade it will receive during the day. A weeding fork can be used to loosen and remove some of the soil in the crevices and small areas to be planted. Neal likes to amend the removed soil. A dose of fertilizer such as Espoma Plant-tone, which encourages root growth, can be used at this time and should not be repeated.

Neal plants after the danger of frost has passed and takes care to keep the root balls intact as she manipulates the small plants into the amended soil. She takes into consideration a plant's need for sun or shade when she places it. Rocks provide insulation from heat during the warmest days, as well as some protection in cold weather. Planting can continue throughout the growing season.

It is feasible to use seeds instead of starter plants, but gardeners should lightly mist the seeds to keep them moist until germination. Seeds can dislodge easily, but sphagnum moss can be tucked around the seeds to keep them in place. While direct seeding means results will come more slowly, costs will be lower, and eventually the plants will re-seed and propagate. Neal warns that the time will come when perennial rock garden plants will outgrow an area and need to be divided or cut back every spring.

Stepables, technically a brand name, is a term that has come to describe plants that can be walked upon. High-traffic Stepables include red creeping thyme and woolly thyme. Both tolerate full sun well.

Dwarf bulbs are available for colorful additions to rock gardens and can be tucked into out-of-the-way places to provide surprises when they emerge.

Alpine rock thyme and alpine calamint are especially easy to grow; sedums, campanulas and rock or wall cress work well; columbine, dianthus and poppies are available in smaller varieties especially suited to rock gardens. And there's a low-growing variety of Allium, a member of the onion family that has a dramatic, long-lasting flower. Creeping phlox, which comes in many colors, can be used in a rock wall or garden as can white, gold, yellow, pink or purple Alyssum. Aster coloradoensis, a variety only 2 inches tall with dainty pink flowers, is another good choice.

The addition of plants around rocks – in walls, between flagstones or in raised beds, tight corners or meandering berms – can add welcome pizzazz to any outdoor area without a lot of initial work and ongoing care