Groundcovers in Winter

A guest post by Shannon Currey.

As much as curling up with a good book, a hot beverage, and a fuzzy blanket is sublime during winter, there’s another activity that inevitably draws me outside. And that’s scouting for winter groundcovers. Now, hear me out on this. It’s not cozy, but it’s an essential part of building a landscape that’s sound ecologically.

We know groundcovers pack all kinds of ecological power—improving soil, reducing erosion, slowing stormwater runoff, providing cover for wildlife, reducing weed competition—but we tend to focus on the growing season when selecting them. It’s equally important, and arguably more important, to ensure we’re attending to those benefits during winter. During the growing season, there may be tons of coverage, but does the winter garden have enough? Are there big bare patches and/or vast expanses of mulch?

Exploring public gardens and scouting for winter groundcovers offers opportunities to improve your landscape. You’ll find stalwarts like Polystichum acrostichoides (Christmas fern) at Longwood Gardens, Kennett Square, PA. © Izel Native Plants

One of the best ways to assess your groundcover game is walking your garden in the dead of winter and early spring. It’s easier to see where you need more plants and better coverage. This is also an excellent time to scout public gardens and natural areas to see what’s there. Which low-growing plants are still above ground and taking up space? Do they have foliage that’s evergreen or semi-evergreen? Are there species forming colonies? Are there plants with basal rosettes or clumps of basal foliage that are present even when the upper stems and leaves have died back? These are good candidates for winter groundcover, and you can evaluate them based on appropriateness for your site conditions.

The basal foliage of Packera aurea (golden ragwort) creates ground covering clumps in this Pennsylvania garden. © Wendy Brister

For those of you with snow cover, this exercise is a little trickier. Start your explorations virtually or in print (it’s a great reason to dive into those stacks of garden books you’ve been meaning to consult). Once the thaw reveals the landscape, you can get out there and scout for yourself. Ensuring you have plant coverage underneath the snow will be critical for managing runoff and providing those other ecological services when the melt begins.

My stack of books for winter reading. © Izel Native Plants

Whether you can get out and see what’s there now or you’re doing your browsing mentally, we wanted to highlight a few options. Izel Native Plants asked several experts on perennial plants what winter groundcovers they would recommend. Our contributors offered a range of options, and because there was overlap in what they suggested, we’ve pulled a few from each. The list isn’t exhaustive, but it’s a great place to start.

Expert Picks:

Wendy Brister is Marketing Director at Cavano’s Perennials. She’s a landscape designer, horticultural educator, and veteran organizer of the Native Plants in the Landscape Conference in Millersville, PA. Here are some of her favorite evergreen plants to add life to the winter garden.

• Packera aurea (golden ragwort) and Packera obovata (roundleaf ragwort) are the most familiar species. Both have semi-evergreen basal foliage that forms dense rosettes to crowd out competitors. They’re widely adaptable and will reseed unless deadheaded.
• Waldsteinia fragarioides (Appalachian barren strawberry) forms dense, evergreen mats of foliage. It spreads vegetatively via shallow rhizomes (underground stems) but is not aggressive. Tolerates a wide range of soils but prefers slightly acidic, humusy sites. It struggles in heat and humidity and does best in climates with cooler summers.

The leaves of Heuchera americana (American alumroot) are known for their coloration and venation. The term “evergreen” is used to describe persistence. Winter foliage, however, doesn’t always remain green. Alumroot takes on lovely shades of bronze and silver. © Izel Native Plants

• Heuchera americana (American alumroot) and Heuchera villosa (hairy alumroot) have semi-evergreen leaves that usually rise above leaf litter. H. americana and its cultivars often have beautiful colors and interesting venation; the leaves of H. villosa and cultivars are velvety and sculptural. H. americana leans toward moister, richer soils, while H. villosa can tolerate drier conditions if placed in shade.

The leaves of Phacelia bipinnatifida (fernleaf phacelia) form persistent basal rosettes late in the growing season. Plants will bloom the following spring, thereby completing their life cycle. © Izel Native Plants

• Phacelia bipinnatifida (fernleaf phacelia) is a biennial wildflower that forms a basal rosette of semi-evergreen foliage in its first year. Purplish blooms on slender stems follow the second year. Although it’s a biennial, it will reseed opportunistically and fill spaces if allowed.

Sam Hoadley is the Manager of Horticultural Research at Mt. Cuba Center in Delaware. Sam’s suggestions for winter groundcovers include Carex, a genus he’s been exploring through plant trials.

• Carex plantaginea (plantainleaf sedge) has lustrous, textured leaves that give it a distinctive look. It’s very ornamental and mostly evergreen. Will re-seed gently.
• Zizia aurea (golden zizia), also called golden Alexander, is an upright perennial with leathery green leaves and a basal rosette that is semi-evergreen. It forms lovely, small colonies and is an early spring bloomer.

Carex cherokeensis (Cherokee sedge) in a woodland setting at Sarah P Duke Gardens, Durham, NC . © Shannon Currey, Izel Native Plants

• Carex cherokeensis (Cherokee sedge) forms a dense crown of shiny, dark green foliage that’s evergreen in warmer climates and semi-evergreen in the northern part of its range. It spreads slowly via short rhizomes and re-seeding and may eventually form a colony. One of the top-rated sedges in Mt. Cuba’s Carex trials, where it did not spread via rhizome, but mostly formed larger clumps and seeded in gently.

Pachysandra procumbens (Allegheny spurge) and Sedum ternatum (woodland stonecrop) in a winter Mid-Atlantic garden. © Izel Native Plants

• Pachysandra procumbens (Allegheny spurge) has toothed leaves that develop attractive silvery veins as they mature. The foliage is evergreen within its native range (zones 6 and warmer), but it is hardy in colder climates where it should be considered deciduous. It’s well-behaved and will spread slowly via rhizomes.

Patrick Cullina is an award-winning horticulturist, landscape designer, and consultant who directed horticultural operations on The High Line and at Brooklyn Botanic Garden, among other public gardens. Pat’s favorites include:

• Dryopteris marginalis (marginal woodfern) is a clumper with leathery, evergreen fronds. Its habit is upright and arching, and planting several together creates a nice mass. Prefers moist, slightly acidic soils high in organic matter but will tolerate drier conditions than many ferns.

Sedum ternatum (woodland stonecrop) remains evergreen, and charming as ever, through winter.  © Izel Native Plants

• Sedum ternatum (woodland stonecrop) is a cute, succulent creeper that spreads vegetatively and by seed but isn’t aggressive. Foliage is light green and evergreen. Enjoys good drainage and bright sun but is more tolerant of moisture and partial shade than most other sedum.

Carex laxiculmis (blue wood sedge) is still going strong in late January in this Mid-Atlantic garden. © Izel Native Plants

• Carex laxiculmis (blue wood sedge) and the cultivar cultivar ‘Hobb’ Bunny Blue® are just two of the many sedges that work well as ground covers. Patrick uses low-growing sedges extensively, and we picked out some from the many choices. These two have blue foliage that’s visually appealing, and being evergreen makes them even better. They’re tougher than they look and will gently re-seed. Carex flaccosperma (thinfruit sedge) is similar in appearance, with a more southern range.

Mark Dwyer is a landscape designer who spent many years managing public gardens in the upper Midwest. He currently runs a residential landscape design firm (Landscape Prescriptions by MD) and is garden manager for the Edgerton, Wisconsin Hospital Healing Garden. Mark’s suggestions include:

• Carex platyphylla broadleaf sedge has wide, bluish foliage that makes it one of the more ornamental species. With blades up to 1” wide, its arching habit provides good coverage, and it will spread gently. Evergreen in warmer climates, it’s semi-evergreen in Mark’s upper Midwest region.

Polystichum acrostichoides (Christimas fern) may lose its upright form during winter, but the cascading fronds have their own charm. © Izel Native Plants

• Polystichum acrostichoides (Christmas fern) is very adaptable and reliably evergreen. Foliage can become a bit tatty by winter’s end, but it continues to provide coverage as new foliage emerges in early spring. Will often spread gently via spores when it’s happy.

The leaves of Tiarella cordifolia (heartleaf foamflower), seen here in late spring, will persist through winter and take on bronze and silver hues similar to those of alumroot. © North Creek Nurseries

• Tiarella cordifolia (heartleaf foamflower) like its Heuchera cousin, offers beautiful leaf color and venation, and cultivars expand the options. The leaves persist into winter, and are evergreen in the warmer regions of its native range. In Mark’s colder region, the leaves look great when they’re not covered with snow.

Lastly, I’ll add a few of my favorites from here in North Carolina.

• Chrysogonum virginianum (green and gold) is a surprisingly tough, low-growing groundcover with hairy stems and leaves. Spreads rhizomatously to form colonies, but the extent of that can vary. Chrysogonum virginianum var. australe spreads much more readily via stolons and can provide more rapid coverage. Foliage is semi-evergreen and mostly evergreen in warmer climates.

Antennaria plantaginifolia (plantain-leaf pussy toes) in a woodland rock garden. © Uli Lorimer

• Antennaria plantaginifolia (plantain-leaf pussy toes) is a charming, semi-evergreen groundcover. Fuzzy, paddle-shaped, gray leaves form basal rosettes. Erect stems rise above the foliage in spring to produce equally fuzzy, paw-shaped clusters of flowers (hence, the pussytoes moniker). Forms dense, matlike colonies under ideal conditions.

The basal rosettes of Erigeron pulchellus (robin’s plantain, hairy fleabane) are visable during winter in my central North Carolina garden. © Izel Native Plants

• Erigeron pulchellus (robin’s plantain, hairy fleabane) forms basal rosettes that are evergreen in warmer climates and semi-evergreen in colder regions. It will colonize vegetatively but is not aggressive. A member of Asteraceae (Aster family), it produces daisy-like flowers on tall stems in mid- to late spring.

All these suggestions are adapted to shade conditions, and some do quite well under the shade of taller, sun-loving perennials (e.g., Packera, Carex cherokeensis, Carex laxiculmis, Erigeron pulchellus, Sedum ternatum). The latter are good choices for layered plantings on sunny sites. And there are other species that do well in full sun on their own but aren’t on this list, like Penstemon digitalis, Oenothera fruticosa, and Deschampsia cespitosa.

This time of year, when most of the landscape is dormant, is a perfect time to embrace the quietness and cast your eyes downward. Walk your own outdoor spaces and explore local gardens and natural areas to see what’s happening on the ground. The plants you see there and on this list can help you fill gaps and contribute to the plant community you’re building. It’s a worthy winter endeavor that warms the soul.

Shannon Currey is a horticultural educator with Izel Native Plants. She’s worked in the nursery trade since 2006, and has established herself as an expert on graminoids, including native grasses and sedges. She serves on the North Carolina Plant Conservation Program Scientific Committee and the board of the Perennial Plant Association. Shannon lives in Durham, North Carolina.

About Izel Native Plants

Izel Native Plants is an online retailer for native plants. Their unique model helps gardeners and professionals source plants to create environmentally sound landscapes that support local ecosystems. Their website combines the inventories of leading wholesale growers, giving you access to the wide range of native plants they grow. To learn more about or to order these fantastic native plants, go to izelplants.com.