GARDENING IN HARMONY WITH NATURE IN THE NORTHEAST

Native Sedges

Very few true grasses are able to flourish in the shade of a woodland. In contrast, most species in the large genus of Carex (the true sedges) love the woodland shade and many are native to the Northeastern deciduous woods.

Carex are grass-like plants with blades that can be narrow to broad. Flowering is usually brief and not particularly showy. For nerds like us, willing to invest some time to get to know the sedges however, the flowers can be intriguing. Flowers are followed by seedheads that can also be quite interesting. The seed are cherished by many woodland animals from the tiny Dark-Eyed Juncos to the big Turkeys.

The main value of sedges from a gardening perspective lies in their foliage that can be upright or mounding, tall or diminutive, spreading or clumping, exhibiting shades of green with blue or yellow tinges to tan in autumn. There are sedges for swampy areas and dry forest mountaintops. Some are even capable of functioning as an ecologically valuable no-mow turf for moderate foot traffic. They give great texture to the woodland floor when massed or function as supporters for more showy accent plants. Like native ferns, native sedges are essential for an authentic healthy woodland garden.

Pennsylvania Sedge

Pennsylvania Sedge (see also the image at the top) is the most prolific sedge in our woods. It forms beautiful arching mounds less than 1′ tall, and spreads quickly, filling in bare spots within a few years and forming a continuous low carpet. Great on their own or as an underplanting for larger woodland plants.

Appalachian Sedge

Appalachian Sedge prefers dryer shade conditions than Pennsylvania Sedge. It grows even on north-facing slopes, where it is a valuable groundcover. Appalachian Sedge forms neat clumps and seems to propagate mostly by seed.

White-Tinged Sedge

Found in even dryer conditions than Appalachian Sedge and able to take some sun, White-tinged Sedge grows naturally on south-facing hilltops in our woods. It forms beautiful mounded tufts that bloom prolifically in a yellowish-white very early in spring. As the season progresses, the clumps flatten and form fantastic radiant shapes. Our local Box Turtles are often found in this area. Maybe they like the White-Tinged Sedge Seed. Self-sows where happy.

Swan’s Sedge

Swan’s Sedge prefers dry, partly sunny sites similar to White-Tinged Sedge. It exhibits quite interesting Q-tip shaped flowers during May and June, during which it can be more easily identified.

Soft-Leaved Sedge

This diminutive sedge has become one of our favorites. It’s color is a very light green, always looking fresh. In late spring / early summer, Soft-Leaved Sedge is covered in hundreds of tiny flowers followed by seeds. The habit is nicely clumping, but it also propagates by underground runners and can easily be divided.

Seersucker Sedge (or Plantain-Leaved Sedge)

Among the sedges, this species may well be one of the showiest. Seersucker Sedge has very wide leaves with pronounced longitudinal veins and dimples all along. When not in flower, this plant is much wider than it is high. Quite showy flowers are exhibited for a brief period of time in early spring on tall stems (if the deer do not find them). Seersucker Sedge can be used as a dense, evergreen ground cover or as an accent plant in medium moisture conditions. It slowly spreads by short rhizomes and is easily divided. We are growing Seersucker Sedge in a colony adjacent to a colony of Christmas Fern, and plan to intermingle the two in a transition region for nice contrast.

Creeping Sedge (Carex laxiculmis)

Blue-tinted, evergreen leaves about half as broad as those of Seersucker Sedge and with a similar clumping habit, make this sedge a nice addition to the woodland garden. We have recently found some volunteer plants around our Spotted Geraniums and are encouraging them to spread. Creeping Sedge apparently likes moist spots such as on the edges of creeks.

Creek Sedge

Similar to Creeping Sedge, Creek Sedge requires lots of moisture such as near creek beds to flourish. We grow it in a low spot around Spreading Globeflower and Blue Cohosh and it is displaying very vigorous fountain-like mounds. Leaves are glossy green 1′ long and 1/8″ wide. A colony of Creek Sedge can look rather wild and is a good selection for naturalized wet areas.

Rosy Sedge (or Curly-Styled Wood Sedge)

We found Rosy Sedge growing wild in a rather dry area on our property. Mature clumps exhibit clouds of flowers and seeds in spring. Rosy Sedge forms nice clumping mounds that are upright early during flowering time, but tend to completely flop over during late spring. We really like the look of these flopped-over heavy seed-bearing stalks. The plant becomes more arching, fountain-like in summer when new vegetative growth appears from the center of the clump. It is easily confused with Carex radiata (below), which however prefers much wetter sites.

Eastern Star Sedge

After acquiring a few of these at a native plant nursery, and planting them in an area around Spreading Globeflower, we found it survives exclusively in wet bottomlands. We are now planting more of them around Virginia Bluebells. Eastern Star Sedge is a favorite of ours due to its graceful symmetric narrow foliage.

Tussock Sedge

A true wetland plant, Tussock Sedge forms high hummocks (also called tussocks), elevating the plant out of the standing water. Old leaves remain brown under the fresh green foliage. Brown flowers are held up high. We have a huge colony of these in a neighboring swampy area, where it is associated with Skunk Cabbage and Cinnamon Fern. Tussock Sedge can also be grown without standing water in wet soil but it is truly at home in seasonally flooded areas.

Gray’s Sedge

This is quite a showy sedge. We like to call it “Morningstar Sedge”, because its big spiky seed heads look like a medieval morningstar weapon. For a few years we had a nice colony in a wet spot, but the plants declined until they were completely gone. A year later however, seedlings started to emerge in the entire area, so we may be seeing the true habit of this plant just now: short-lived and prolifically self-seeding where happy.

Long-Beaked Sedge

We have planted an entire flat of this clumping sedge in a shady area among self-seeding White Wood Aster, and the plants are thriving in their 2nd year. Carex Sprengelii is taller and more upright than your typical native sedge, and the seed-heads are quite showy. Turkeys have already come foraging to this patch during seed-bearing time.

Grass-like plants other than sedges are few and far between in the woodlands. We have tried to grow the beautifully clumping Little Bluestem Grass in our meadow, but it clearly does not do well and would like more sun.

So, here are the few native grasses and rushes that can cope with the shade:

Indiangrass

Indian Grass is a tall clumping grass that competes very well in the shady meadow. It has important wildlife value, harboring many insects such as grasshoppers and skippers. Bear in mind that it grows very tall, shading out a lot of smaller perennials, but with the right companion plants, such as the freely self-sowing late figwort and monarda species, it works for us.

Tufted-Hair Grass and Wavy-Hair Grass

Tufted-Hair Grass is probably the best of the bunch. It forms beautiful dark mounds of foliage a foot in height and almost two feet in width, covered by a cloud of flowers in summer. We are mixing this species with Spring Ephemerals that go dormant when the grass fills in. It also looks great in summer with Bluestar and Wild Indigo. Also in the genus Deschampsia, Wavy-Hair Grass is much more diminutive with very fine dark green foliage topped by wavy flowers. We still have to find a situation where this one can shine.

Path Rush and Soft Rush

Finally, there are two rushes growing in our woodlands. Path Rush, as the name suggests, near areas with foot traffic, and Soft (or Common) Rush in wet spots. We like Path Rush for it’s nice clumping habit. It can be intermingled with Pennsylvania Sedge, where it appears more upright than the sedge. Soft Rush is also very straight and upright, growing 2′ tall or more. It’s an ok plant for the shady, moist meadow, playing well with the sedges and forbs around it, since it lets a lot of light filter through.