When it comes to groundcovers, gardener’s should follow Alexander Pope’s advice and “consult the genius of the place”; in other words, we should mimic what happens in the wilder areas around us. For example, take a walk through a mid-coast Maine natural area with an eye to the ground and you are likely to find a tapestry of bunchberry, lowbush blueberry, starflower, Canada mayflower, and ferns. Here the blueberry thrives, there the bunchberry, and so on, each species occupying the spots most suitable to its needs. It is this tapestry of colors and textures that we find so engaging, one species flourishing in the filtered shade of a small tree, another taking advantage of the brighter spots. This intermingling of species creates garden scenes that are far more interesting than the monotonous expanse of one species.
In Marjorie’s Garden, groundcover is largely a mix of the low-growing plant species endemic to the mixed spruce and hardwood forests of mid-coast Maine. Most are native herbaceous perennials. Add a few purchased plants that have naturalized in our garden and the result is an intermingling of various leaf shapes, textures, and colors. Our work is largely deciding what to call “weed” and what to cultivate.
You can find foamflowers (Tiarella cordifolia) growing in small patches along stream banks in woodlands throughout New England, individual plants reaching 6 to 8 inches tall and 11 inches wide with slightly hairy heart-shaped leaves and foliage that is often marked with maroon patches. These colonies spread vegetatively by runners. In spring the plants give rise to spikes of starry white or pink flowers that move in a gentle breeze like foam on a sea of green.
Many of the foamflowers we find in commerce are the products of intense hybridization and selection to produce varieties of various foliage coloration and degrees of leaf dissection. For example, in Marjorie’s garden we are growing the white-flowered ‘Running Tapestry’, its dark green leaves boldly marked by deep maroon veins. We were sold on this evergreen variety when we saw the coppery tones of foliage in early spring as the plants emerged from under the snow.
Foamflowers are easily grown in well-drained soil in part shade to full shade. They prefer humus-rich, moisture-retentive soil that does not dry out; wet soils, particularly in winter, can be fatal. You may want to remove the spent flower stalks after the blooming period to fully enjoy the summer foliage.
Natural colonies of Canada mayflower (Maianthemum canadense) grow in Marjorie’s Garden, their glossy green oval leaves soaking up dappled sun beneath white pines and spruce. They seem to thrive in the thin acidic soils beneath these trees. Growing from three to six inches in height, the plants in some colonies have mostly infertile shoots and seldom flower, while those in other colonies send up two-inch-high flowering stalks each spring, the tiny white flowers arranged in pairs along the stalks on slender pedicels. Small native bees collect pollen from the fragrant flowers.
The flowers are followed by quarter-inch round berries, green at first, speckled pale red at maturity. The berries are eaten by ruffed grouse, white-footed mice, and chipmunks, all of which help spread the seed around.
Starflowers (Trientalis borealis), dainty plants rising only four to eight inches from the ground, are always a joy to find blooming in the garden during May and early June. They often mingle with the Canada mayflowers in our garden, developing open colonies from slender rhizomes. The star-shaped white flowers, about one-half inch across, often have seven petals, but sometimes as few as five or as many as ten. While tolerant of thin acidic soils, they also thrive in cool wooded areas with peaty soils.
We are lucky to have starflowers as part of the native flora in our garden. They can, however, be planted. The New England Wildflower Society ( Framingham, MA) recommends transplanting seed-germinated plants from containers in spring, or planting dormant rhizomes into an acidic moist soil in late summer.
Growing only a few inches high, bunchberry (Cornus canadensis), a native dogwood, is one of several plants of mossy areas. Together with lowbush blueberries and ferns, bunchberry helps fill in small niches where the moss languishes to create a carpet of colors and textures. Like its tree-form relatives, the flowers of this dogwood are in tiny white clusters surrounded by four large white bracts, giving the appearance of a single blossom. The fruits, borne in clusters (or bunches, as indicated by the common name), are coral red.
Many New England gardeners are lucky to have bunchberry growing wild on their property, often in the cultivated garden. It grows most vigorously in partial shade, preferring soils that are moist but well drained and acidic.
Lowbush blueberries (Vaccinium angustifolium) grow in small patches throughout Marjorie’s Garden, wherever the soil is sufficiently acidic (pH 4.5 to 5.5), high in organic matter, and well-drained. They bloom to the delight of bumblebees in May and, in the sunnier spots, produce an abundance of quarter-inch blue-black berries that we share with the garden’s resident wildlife.
Beneath the high shade of an old white pine, in a bed constructed to grow elderberries, the ground is covered with
volunteer violets. It all began with seeds dropped from pots on the porch railings several years ago. Each year since, the blanket of violets has spread so that now it covers the ground beneath the elders with deep purple flowers from mid-May through June.
All of these groundcovers grow in Marjorie’s Garden. With the exception of the violets, they were flourishing here before we were. In one special corner of the garden, an area no more than 100 square feet surrounding a tall red maple, Canada mayflower, starflower, lowbush blueberries, and bunchberry grow together, each forming small colonies where conditions allow it to thrive. It is a special place late in day when the sun drops behind the distant spruce and the white flowers of these native groundcovers glow in the gloaming.