Covering All Your Options

Andrew Bunting

In the last 30 years, perennials—especially native perennials—have continued to grow in popularity. More and more homeowners are interested in ways that they can create habitats in their home garden by adding plants as a food source for birds (including hummingbirds), mammals and myriad pollinating insects.

Native groundcovers are low-growing plants that help to quickly cover the ground while adding beauty to the garden. These plants tend to be quick to spread and establish themselves. Additionally, some families of native ferns and sedges, like Carex, are deer-resistant.

The Christmas fern, Polystichum acrostichoides, is called this because of its evergreen fronds that reach 8 to 12 in. and are still ornamental at Christmas. One of its greatest attributes is that it will grow in extreme shade, as well as dry shade. Over time, the Christmas fern will make large masses, which are important ornamentally for the winter landscape. The fronds can be cut back in mid-March and then new fronds will emerge and refresh the appearance of the plant.

The lady fern, Athyrium filix-femina, has lacy, upright, light green fronds up to 2 ft. long. As the fronds emerge the fern has a vase-like appearance. Spreading over time, the lady fern brings a fine textured effect to the shady parts of the garden. It combines nicely with other woodland plants such as foamflower, Tiarella, and creeping phlox, Phlox stolonifera.

Adiantum pedatum, the maidenhair fern has very delicate and elegant foliage. The palmate arrangement creates finger-like fronds reaching up to 2 ft. tall. This fern can take deep shade conditions and in the wild, grows in rocky ravines. It combines nicely with the bolder textured ground covering Asarum canadense, or Canada wild ginger, which has heart-shaped leaves and is mat-forming.

Just 10 years ago there were hardly any native sedges available for use in the garden. These grass-like, mostly woodland, ground-covering plants have exploded in popularity in recent years. There are hundreds of sedge species and dozens of great native sedges. Sedges are characterized by clump-forming foliage, often low to the ground, which can spread over time and is very tolerant of the shade. Probably the most popular is the Pennsylvania sedge, Carex pensylvanica, which has fine green foliage. This plant is tolerant of both moist and dry shade conditions. Carex eburnea reaches 6 to 12 in. tall and tolerates full shade. In my woodland garden I grow Carex grayi, which has very ornamental foliage and attractive seed heads, as well. For sun to part shade conditions, I love the fullness of Carex cherokeensis, which quickly established full clumps and airy and attractive flowers above the foliage. At the Mt. Cuba trials, the Wood’s sedge, Carex woodii, was top-performing with tufts of medium green narrow leaves reaching 14 in. tall.  Additionally, Carex montana, the mountain sedge, creates graceful clumps.

Some of the best ground-covering native plants are the foam flowers, Tiarella cordifolia. They are characterized by leaves that are somewhat triangular, often with attractive burgundy markings. Quick to colonize in the garden, they are called foam flowers due to the abundance of spikes of tiny white flowers that occur early in the spring, creating a “frothy” or “foam-like” appearance. Brandywine was given the Gold Medal designation by the Pennsylvania Horticultural Society. Pink Skyrocket has soft pink flowers. The foliage can be semi-evergreen in some climates.

Phlox divaricata (wild blue phlox) and Phlox stolonifera (creeping phlox) are quick-covering native woodland phlox. These woodland phlox are mat-forming with flowers reaching 8 to 10 in. tall. There are selections with myriad color forms, including white, pink, blue and purple. These phlox can be an early nectar source for swallowtail butterflies, clearwing moths and hummingbird species. At the Mt. Cuba trials the following were the best performing cultivars: Phlox divaricata Blue Moon and Phlox stolonifera Home Fires, Pink Ridge and Sherwood Purple.

Packera aurea (syn. Senecio aureus), the golden ragwort, has been gaining in popularity because it is quick to establish in the garden. This aggressive spreading woodland native blooms early in the spring with upright stems 2 to 3 ft. tall topped with dozens of skyward-facing, bright yellow, daisy-like flowers. It can thrive in both sunny spots and dappled shade and is a good early pollinator plant for native bees.

Heuchera villosa, the hair alumroot, is a mounding broadleaved perennial that can be evergreen to semi-evergreen in many parts of the country. It is often found growing throughout the East in rich woodlands and wooded slopes. It produces an abundance of 1 to 2 ft. tall spikes of white flowers from July into the early fall. It attracts many native bee species, including a specialist bee, Colletes aestivalis. Autumn Bride is a popular cultivar.

The dwarf crested iris, Iris cristata, is a botanical gem on the woodland garden. Over time it will spread into tight mats of fine-textured, pointed, arching foliage. The upward facing flowers have six spreading, petal-like parts with three that are violet with intricate markings of violet, yellow and white. Powder Blue Giant has soft blue petals and Tennessee White has alabaster white petals with yellow markings. This low-growing iris thrives in part shade to shade in moist, organic, rich, acidic soils. It can be used en masse in the woodland garden, or can be used to fill small niches next to a patio.

The native ground-covering perennials offer many ornamental characteristics as well as fill functional niches in the landscape. Most of them contribute to making the garden an ecological haven by offering shelter and a pollen source for many native pollinators. GP

Andrew Bunting is the Vice President of Horticulture for the Pennsylvania Horticultural Society (PHS), which uses horticulture to advance the health and well-being of the Greater Philadelphia region. To learn more about PHS, or to become a member and support greening initiatives in over 250 neighborhoods, visit PHSonline.org.