Those of us contending with the shadier portions of our gardens may sometimes feel that we don’t have enough choices, particularly when it comes to ornamental grasses. But there is light at the end of the tunnel! While many types of grass typically need full sun to flourish, Carex pensylvanica thrives in dappled sunlight to deep shade. A native to deciduous woods in Wisconsin, Pennsylvania Sedge is one of the earliest blooming woodland plants, forming graceful arching mounds in spring. May also be known as Oak Sedge.
Pennsylvania Sedge is lovely when planted on its own or to soften bed lines and walkways. When planted in groups or masses, its fine-textured, glossy, and bright green foliage creates a lush, undulating carpet. It can also be used for planting under larger plants such as Large White Trillium, Virginia Bluebells, Jacob’s Ladder, Allium, and Wisconsin Native Ferns, acting as a living green mulch to cover bare soil, fill in gaps, and suppress weeds. It’s an excellent choice for stabilizing sandy soils, their roots extend 1-2 feet, forming large colonies of underground rhizomes.
For those looking to replace a traditional turf lawn, Pennsylvania Sedge is a wonderful substitute when planted in drifts or masses, especially in shady areas where traditional grass struggles. Plant 12-inches apart to create a lawn that can be mowed to 3-inches or slightly lower, roughly 1 to 3 times a year. Thriving under oaks, hence its alternative name ‘oak sedge,’ plant in groups to light up the darkness with vibrant greenery and velvety texture.
Delicate flowers in April or May are followed by seed heads, which are a treat for Dark-Eyed Juncos, turkeys, sparrows, Eastern Towees, and other songbirds. Providing cover for many migratory birds including waterfowl, sandhill cranes, mallards, prairie chickens, and sharptail grouse, Pennsylvania Sedge is also a larval host to several moths and skippers including Satyrodes appalachia, Euphyes dion, and Euphyes vestris.
Pennsylvania Sedge will tolerate a wide range of conditions from wet to dry soil and from part sun to full shade. A late winter or early spring clipping will promote new growth. Keep moist while it establishes and water deeply as needed or every two weeks thereafter. To increase lawn space or groundcover mass, divide clumps in early spring and replant.
Pennsylvania Sedge is generally pest-free. It’s tolerant of Black Walnut Toxicity. Deer and herbivores typically find Pennsylvania Sedge unpalatable.
Commonly used on green roofs, as it can withstand heat, high winds, and varying moisture levels throughout the year, it also provides habitat for wildlife in urban environments, adding to the biodiversity value of green roof systems. With its elegant, tufted appearance, Pennsylvania Sedge softens roof edges, adding movement to an otherwise static architectural component.
Pennsylvania Sedge combines well with larger woodland plants such as Red Milkweed (Asclepias incarnata), Wild Senna (Cassia hebecarpa), Yellow Coneflower (Ratibida pinnata), Prairie Phlox (Phlox pilosa), Coralbells (Heuchera spp.), Prairie Smoke (Geum triflorum), and Canadian Columbine (Aquilegia canadensis).
Its fine foliage provides contrast to broad-leaf perennials such as Hostas (Hosta spp.), Hellebores (Helloborus orientalis), and Hydrangeas (Hydrangea spp.).