By Elaine Mills, Extension Master Gardener
Photos by Elaine Mills
In the fall of 2020, the coordinators at the Glencarlyn Library demonstration garden in Arlington added three new native ground covers beneath the dogwood tree the near the Third Street entrance. Homeowners might wish to introduce these attractive and reliable plants in the shady sections of their own yards.
Marginal Wood Fern (Dryopteris marginalis) is a non-spreading evergreen perennial that forms a vase-shaped clump from 1 to 3 feet tall and wide. Its fiddleheads emerge in early spring covered with brown scales and unfurl into compound, deeply cut fonds with 12 to 20 pairs of leaflets. The plant’s spore-bearing structures (sori) appear along the edges of the leaflets on the underside of the fronds from June to October.
This low-maintenance fern is very tolerant of dry shade conditions once established, although for best display it should be sheltered from strong winds. It has no serious pests or diseases and is rarely damaged by deer. The fiddleheads contain toxic compounds and should not be consumed by humans.
Marginal Wood Fern can be used either as an accent plant mixed with bulbs and other native perennials or planted in masses in a woodland garden. It will remain attractive through the winter months, providing interest and offering cover for birds.
While native to the Southeast, Allegheny Spurge (Pachysandra procumbens) grows very well in Northern Virginia. This clumping, semi-evergreen perennial sends up tightly furled new growth in early spring to replace the previous year’s foliage. The scalloped leaves are initially marbled with pale green or purple and then turn a solid green as the season progresses. Fragrant white flowers appear on pink stalks in April.
Unlike the non-native Japanese Pachysandra (Pachysandra terminalis), this native plant will not overgrow an area. It is also an excellent replacement for invasive English ivy, vinca, or liriope. Allegheny Spurge plants reach 6 to 10 inches in height and slowly spread by rhizomes to form colonies up to 2 feet wide. A ground cover can be established under trees, near foundations, or along walkways where lawn growth is poor by placing starter plants about a foot apart. It grows best in moist, well-drained, organic, acidic soil and tolerates dense shade and drought. It has no serious pests or diseases and is rarely damaged by deer.
Foamflower (Tiarella cordifolia) is perhaps the showiest of the three plants with heart-shaped, lobed leaves and airy spikes of tiny white flowers that attract small bees, flies, and butterflies from April to July. This clump-forming herbaceous perennial grows from 6 to 12 inches high and spreads quickly by stolons (above-ground stems). When planted en masse on shady slopes, it helps control erosion.
Foamflower prefers partial to full shade and soil that is neither too wet nor too dry. It has no serious pests or diseases, tolerates rabbits, and is seldom severely damaged by deer. Its leaves may turn red-bronze in fall, and it can remain evergreen in mild winters. This lovely native can be used in containers and borders as well as in rock and woodland gardens.