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Super Sedges: Using North American Carex in the Garden

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No doubt about it, people love lawns. They love the neat look of turfgrass, the seas of green. However, lawns are a problem. A big problem. Lawns fragment valuable habitat, displace wildlife and pollinators, encourage the overuse of herbicides and pesticides and need emissions-heavy machinery for their upkeep, even in the most awkward of medians, strips and slopes. In the face of a changing world, the lawn, and the idea of what a lawn is, must change too. Luckily there is a humble, Clark Kent-ish genus of plants poised to help: Carex.

Carex texensis serves as a low-maintenance lawn surrounding the trees and shrubs in this courtyard. Photo courtesy of Hoffman Nursery.

Carex texensis serves as a low-maintenance lawn surrounding the trees and shrubs in this courtyard. Photo courtesy of Hoffman Nursery.

Carex comprises affable, unassuming species that spend most of their time pretending to be something they’re not. This expansive collection of wetland or woodland “true sedges” look and grow like grass but are not quite grass, really. With their doppelgänger nature, these clever pest-proof (including deer and rabbit), disease-free fraudsters just might be the key to saving our environment in a post turf-lawn world. By replacing traditional lawns (in whole or in part) with native carex, mixing them with ferns to create woodland meadows or subbing them in for non-native groundcovers, the gardener can help repair and connect pockets of natural habitat and provide host plants for pollinators. Carex pensylvanica alone can host 36 types of butterflies! 

Sedges as Turf Alternatives

Variegated cultivars of Asian species like Carex morrowii 'Ice Dance' have long been staples for Japanese-inspired, shaded plantings. However, a large roster of North American species are emerging—or, rather, re-emerging—as forefront no-mow replacement solutions for turfgrass, especially in shade, where sod tends to struggle. With their semi- or fully evergreen leaves and beautiful arrays of texture and color, these natives are flexible designwise: there’s one for nearly any grassy use, and they can step in for non-native or potentially invasive groundcovers and ornamental grasses, too. And those for lawn replacement need trimming only a few times a year.

Pennsylvania sedge is a fine-textured species suitable as a low-traffic lawn in dry shade. It can also take sun if the soil remains moist.

Pennsylvania sedge is a fine-textured species suitable as a low-traffic lawn in dry shade. It can also take sun if the soil remains moist.

The range of carex suitable for lawns in low-traffic areas or outfitted with stepping stones is wide and exciting. A go-to is C. pensylvanica, or Pennsylvania sedge. Hardy in USDA Zones 3 through 9, it’s widely distributed across most of eastern and central North America. Naturally found in sandy, less-than-great soils, it tolerates moist, sunny locations as well as dry shade. Pennsylvania sedge creeps into languid five- to twelve-inch-wide mops, with a soft, fine texture that makes the species particularly reminiscent of turfgrass. When planted en masse, it creates a wonderfully dense, flowing, semi-walkable pool of green when left unmowed. It can also be shorn two or three times a year, with the mower set high, for a neat and trim lawn.

There are many similar species in this vein, including C. rosea, which can handle slightly deeper shade and more moisture. In the humid South, C. texensis is emerging as a good turf replacement for part shade, while C. perdentata is on the rise in the hot Southwest. These species can follow a mowing regimen similar to Pennsylvania sedge. For a no-mow option, there’s the aptly named lawn sedge, C. leavenworthii, which tops out at four to six inches.

Sedges for Mixed Borders

Carex flaccosperma, shown here in winter, is a coarse-leaved sedge that makes a hardworking ground cover. Photo courtesy of Hoffman Nursery.

Carex flaccosperma, shown here in winter, is a coarse-leaved sedge that makes a hardworking ground cover. Photo courtesy of Hoffman Nursery.

Other species can go to work imitating traditional, non-native garden perennials. Carex laxiculmis (Zones 4–7, with reports of success in Zones 8 and 9) is one of the most colorful and garden-worthy options. Also known as creeping sedge, it has a broad North American distribution, occuring in moist woodlands and streamside locations from Ontario and Quebec south through most of the Eastern and Midwestern states, with some records of Southeast populations. Its strappy, semi-evergreen to evergreen, blue-green foliage greatly resembles that of non-native Liriope or black mondo grass and can often be swapped in for these. A noted natural cultivar, 'Hobb', also sold as Bunny Blue, boasts distinctively powder-blue glaucous foliage. Like most carex, creeping sedge needs a single haircut each year, timed to mind the moths and butterflies that it hosts. Blue wood sedge (C. flaccosperma) looks similar with its bright blue summer coloring, while C. blanda, or common wood sedge, is also reminiscent but less blue. It may be hiding in your landscape already.

Carex plantaginea boasts relatively wide foliage with a seersucker texture. Try it in place of liriope or even hostas.

Carex plantaginea boasts relatively wide foliage with a seersucker texture. Try it in place of liriope or even hostas.

For even bolder texture, there’s the larger-leaved C. plantaginea, known as plantain-leaf or seersucker sedge. It, too, can take the place of liriope or daylily (foliage) in the shade to part-sun border. Hardy in Zones 4 through 8, it’s another broadly native plant of wooded slopes from Nova Scotia to Alabama. One of the showiest carex, it bears substantial, inch-wide, crinkled lime-green leaves that do call to mind seersucker fabric. It’s especially effective massed along foundations, paths and formal walkways, and it is large enough to be a deer-proof replacement for narrow-leaved hosta cultivars.

Palm sedge (C. muskingumensis) likewise is another bold and true ornamental for mixed borders, where it can take over for many similarly sized non-native grasses. Stately tall and wide whorled and branching chartreuse foliage gives it a vaguely tropical, palm-like appearance that belies its hardiness (Zones 4–8). This species is generally a moisture-loving, semi-aquatic plant native to streambanks and lowland woods of central North America, but, like most carex, it shows amazing versatility, tolerating drier garden locations and less than perfect sites, including clay. Uncommon but beautiful cultivars 'Oehme' and ‘Ice Fountains’ each offer striped variegation, creating a suitable replacement for Japanese forestgrass (Hakonechloa macra cvs.) or variegated Miscanthus.

Sources for Sedges

Carex can be challenging to establish from seed. Plants are generally sold in pots or plugs, which represent an easy and economical way to establish swaths of modern lawn. If you can’t yet find a good selection of sedges locally, try the following mail-order retail sources:

Izel Native Plants: This company was founded to connect gardeners with wholesale native-plant nurseries. Orders are fulfilled from various wholesalers, matching the customer with the closest regional source when possible. Carex species are available in flats.

Prairie Nursery: Located in Wisconsin, Prairie Nursery is a retail supplier of native plants and seeds. It sells Carex species singly and in flats.  

Photo credits: Landscape shots (C. texensis and C. flaccosperma) courtesy of Hoffman Nursery, a wholesale grower. Carex pennsylvanica by Krzysztof Ziarnek, Kenraiz/CC BY-SA 4.0. Carex plantaginea by Agnieszka Kwiecień, Nova/Own work, CC BY-SA 4.0.