Q: The shady, narrow walkway beside our city house is a straight 30-foot shot, flanked by beds only a foot wide. Are there any ways to make this dead space come alive? — Mary Pat Prado, Cambridge, Mass.
A: Before choosing a single plant, think about installing an ornamental gate at the street entrance. This will immediately make the walkway feel more private for you and more inviting for visitors. Then establish a focal point in the backyard — a handsome tree or shrub, a large container brimming with brightly colored plants, an extraordinary bench — to draw the eye beyond your narrow corridor. If the paving is in bad shape, replace it or repair it. Don’t wait until after you’ve planted the flanking beds; they’re exactly where you or your paving contractor will need to tread while working on the path.
Ironically, the best plants for your urban site are low-growing perennials adapted to the woods: Besides liking shade, most of them die back in the winter or can be cut to the ground, making life easier when it’s time to shovel snow. Ajuga, lysimachia, and creeping phlox all spread like a carpet. Ajuga reptans ‘Catlin’s Giant’ has burgundy-bronze leaves that supply color long after its deep-blue flower spikes fade in late spring. The delicate-looking foliage of Lysimachia nummularia ‘Aurea’ covers ground quickly and softens the edges of a path. Chartreuse in full shade, it turns butter-yellow in a spot that gets only an hour or so of sun. Phlox stolonifera, which has similarly shaped leaves in light green, is more notable for the graceful flower clusters it sends up on 8-inch stems in late spring. The wild form is usually bluish, but there are also blue, white, and pink cultivars. Vinca minor stays deep green and glossy year round.
To contrast with the horizontal line of the walk, add some slightly taller plants (since foliage and flower stems will bend over into pedestrians’ way after a good rain, it’s best to avoid plants more than 8 inches tall). Tiarellas, for example, have dainty green leaves and, in late spring, produce white or creamy-pink flower spikes. The feltlike, heart-shaped foliage of wild ginger, Asarum canadense, thrives in dark corners. Most pulmonarias have velvety dark-green pointy leaves flecked with white; their little clusters of spring flowers remind me of Virginia bluebells. Lamium maculatum ‘Beedham’s White’ makes a mound of chartreuse foliage, which brightens to lemon-yellow in even a little sun. With any of these small plants, compose distinct patches of each kind rather than spotting them around like pieces on a chessboard. They will soon begin to flow together on their own. And as in any garden, some of the most aggressive players (the vinca, the ajuga, the lysimachia) will need to be restrained from time to time by weeding and clipping back.
Use upright perennials as accents, especially near the ends of the walk, in corners, or near a step or a doorway. Ostrich fern is erect and robust, yet graceful. Nothing is more pleasantly surprising than a few clumps of Jack-in-the-pulpit in bloom; when the leaves melt away in late summer, you are left with brilliant red berries clustered atop 8-inch stems. Hostas, of course, are old standbys for accents in shady places. Seek out a distinctive variety such as H. ‘Krossa Regal,’ which is unusually upright. Prune its flower stalks, though, because they’re almost certain to lean into the path. Come the fall, tuck in some little spring bulbs. Your plot sounds as if it is probably too shady for daffodils, but ideal for snowdrops, golden winter aconites, trout lilies, grape hyacinths, and wood hyacinths.