by Jane Warren
Groundcovers are an important aspect of landscaping that can bring diverse beauty to your yard and at the same time support the natural environment. The Plant
Materials Guide for Lexington (pdf) has a good selection of perennial groundcovers—some have prominent flowers, some have berries that are attractive and provide food for birds and other
animals, and some have interesting leaves. This article focuses on flowering plants but several species of ferns also make good groundcovers.
Native groundcovers can replace aggressive non-native groundcovers like English ivy (Hedera helix), Japanese pachysandra (Pachysandra terminalis), common periwinkle (Vinca minor), and bugleweed
(Ajuga reptans). These commonly used groundcovers have all been highlighted by the US Department of Agriculture as "Weeds of the Week."
Some states have designated these groundcovers to be invasive: Japanese pachysandra in Virginia and Washington DC, bugleweed in 3 states, English ivy in 18 states and DC, and common periwinkle in
25 states. Massachusetts has not yet declared any of these as invasive. English ivy is by far the most destructive of these plants. It is used profusely as a groundcover, but also climbs up trees
and eventually kills them if the vines are not removed. English ivy spreads widely and has long, strong roots. It is commonly used in residents' yards in Lexington and in many areas of the
country, and has invaded some of Lexington's conservation areas. Rock Creek Park In Washington DC is infested with English ivy that has killed many trees.
Barren strawberries (Waldsteinia fragarioides) produce cheerful yellow flowers in late April. The flowers are about ½ inch in diameter with 5 petals, many stamens, and 3 – 6
pistils. The evergreen basal leaves that last into the winter are replaced by bright green leaves in early spring. The name of the plant is based on the similarity of its leaves to those of real
strawberry plants. The fruits are not fleshy or red like strawberries. Each flower usually produces 2 to 6 dry, single-seeded fruits (achenes). The natural habitats for barren strawberries
include woods, thickets, and clearings. They do well in dry or moist soil, too. Barren strawberry is designated as a plant of special concern (one notch below endangered status) in Massachusetts
and Connecticut and endangered in Maine and New Hampshire. Some populations of this plant are threatened by exotic plant species such as garlic mustard, Japanese barberry, and common buckthorn.
Another species of barren strawberry, Waldsteinia ternata, native to Central Europe, Northeastern Asia, and Japan, is sold frequently in nurseries so be sure to buy the native species.
Goldenseal (Hydrastis canadensis) grows 6 to 12 inches tall and bears 2 or 3 attractive 5-lobed leaves 4 – 6 inches across. The stem has a single flower, ½ inch wide, with 3
sepals, several pistils, and many yellow stamens, but no real petals. The prominent, numerous stamens look like thin petals. The white-green flowers that bloom in May are pretty but not showy. A
brilliant red fruit, ½ inch wide with 10 to 30 seeds, that develops in the middle of the leaf in July is spectacular. The name “Goldenseal” comes from yellow scars on the rhizome where the stems
have emerged that resemble wax seals used on envelopes. Native Americans and colonists used these plants for a wide variety of ailments, and the plant is still used for medicinal purposes,
including mouth sores, nasal congestion, stomach ulcers, sore throats, and cancer. Goldenseal is endangered in Massachusetts and 2 other New England states, Vermont and Connecticut. The plant’s
scarcity is the result of collecting the plants from the wild, loss of habitat, and competition of invasive plants. Goldenseal’s habitat is woodlands. Though it prefers rich soil, it can tolerate
other soil conditions. It likes partial shade.
Partridgeberry (Mitchella repens) is a low, creeping evergreen shrub that has slender trailing stems 6 – 12 inches long that lay on the forest floor. The leaves, buds, and
flowers are all quite small, but very pretty and quite conspicuous. In late May, bright pink twin flower buds joined by a white stalk emerge. In early June, white tubular flowers with 4 petals
covered with fuzzy hairs open. Each flower of the pair has 1 pistil and 4 stamens. One flower of the pair has a short pistil and long stamens and the other has a long pistil with short stamens.
This complex construction prevents self-fertilization. The ovaries of the twin flowers fuse after fertilization into an elongated berry with 2 dimples. The bright red fruits that develop in fall
are not particularly tasty so the berries tend to persist into spring. Eventually a variety of birds and mammals eat the berries. Partridges relish the berries. This plant is fairly common in
deciduous and coniferous forests rich in organic soils with partial to complete shade. Some sun and pine needles encourage more blooms.
Shoots of wild ginger (Asarum canadense) emerge in early April. Shortly after, unusual bell-shaped, red-brown flowers 1 inch in diameter form on the ground between 2 leafstalks.
The mature heart-shaped leaves are 4 – 8 inches high and have a beautiful silky shimmer. The rootstock creates a network of stems that result in a thick groundcover. The fleshy root has a
ginger-like flavor, which is the reason for the plant’s name. It is found in woods with rich, moist soil, but can grow quite well in poor, dry soil. It likes partial or full shade. Wild ginger
attracts butterflies and is a larval host of the Pipevine swallowtail butterfly. European ginger (Asarum europaeum) is also easily available at nurseries so be sure to pick the native species.
Heart-leaf foamflower (Tiarella cordifolia) blooms in mid-May. Spikes of small (1/4 inch across), white, star-shaped flowers are on a leafless stalk (raceme) about 6 inches high.
The long, slender stamens give the plant a foamy or feathery look. The attractive leaves look somewhat like maple leaves but are more rounded and smaller. The flowers look particularly pretty
tumbling down a hill. The plants spread from underground stems and can form large colonies. They thrive in moist, well-drained, humus-rich, acidic soils, but also can do well in sandy soils. They
like partial or full shade.
(Sanguinaria canadensis) is an attractive groundcover that flowers in early April and has interesting foliage. More information about this plant and its growing
conditions has been described in an article Glorious April Flowers
Fours species of the heath family are excellent groundcovers with attractive flowers: bearberry (Arctostaphylos uva-ursi), lowbush blueberry (Vaccinium
angustifolium), trailing arbutus (Epigaea repens), and wintergreen (Gaultheria procumbens. Information about these groundcovers, pictures of them, and growing
conditions can be found in an article Meet Lexington’s Heath Family.
Finding these Plants
The Plant Materials Guide for Lexington (pdf) lists nurseries that carry native plants. New England Wild Flower Society’s Garden in the Woods in Framingham
should have all of these groundcovers, but probably not at the same time. Weston Nurseries is Hopkinton has a plant catalog and
availability list on its website. Mahoney’s in Winchester and Russell’s Garden Center in Wayland should have some of the groundcovers described in this article.