Sedges Have the Edge

If you are looking for a lower-growing alternative to native tall grass in your landscape, sedges can provide an edge!

There are nearly 1,500 sedge species in North America. Sedges come from the vast Cyperaceae family of monocoetyledonous graminoid flowering plants(!). The Carex branch of the sedge family typically have a leaf set that has “edges,” the shape of the leaves are triangular, solid stems with the leaves arranged in three ranks. When you hold a sedge leaf, it has sharp edges. This compares to grasses which have alternate leaves in two ranks that are smooth to the touch. Ecologists when determining the identity of a grass-like plant have a saying, “sedges have edges.”

Sedge meadow. Ohio DNR.

Sedges inhabit wet areas. Some form colonies in “tussock” marshes, distinguished by the mounds created by Tussock Sedge. Sedge meadows are a complex ecosystem that harbor a great many forbs, including Joe Pye Weed, Blue Flag Iris, Angelica, Red Milkweed, Great Blue Lobelia, and Bergamot, accompanied by rush species such as Dark Green Bullrush and Woolgrass.

In Wisconsin we are blessed with many wetlands inhabited by sedges including the vast Necedah National Wildlife Refuge and the Horicon National Wildlife Refuge. At the Necedah refuge core studies by the University of Wisconsin have shown that the peat and muck at the bottom of the sedge meadow show a record of plant material that was dated to be 11,000 years old! Amazing! According to Necedah’s website: “The open wetlands, meadows and sedge meadows provide habitat for wildlife including bog-haunter dragonfly, golden-winged warbler, whooping crane, and American bittern.” Here’s a link to the Necedah Wildlife Refuge – a great place to visit if you are visiting Wisconsin:

Long Beaked Sedge (Carex sprengellii) on the left, and Plantain Leaved Sedge (Carex plantaginia) center bottom, in the garden.

In landscaping, sedges are an important component in rain gardens.  Fox Sedge is a common component in our Rain Gardens and Seed Mixes at Prairie Nursery. Fox Sedge can tolerate standing water for a week, but can also withstand long stretches of hot dry soil. During our drought in 2012 Neil Diboll, Prairie Nursery’s president, observed that the Fox Sedge on his property was robust and beautiful even under extreme drought conditions. The beautiful star shaped seed heads that appear on sedges are attractive, and the foliage stays green throughout the summer.  As does Fox Sedge, Palm Sedge also tolerates wet or dry soils, loves clay and provides unique foliage in full to part sun.

Palm Sedge (Carex muskingumensis) in the garden. Photo by Noel Kingsbury.

Beyond the wetland dwelling sedges, there are sedges that are well adapted to just about any landscape. Ivory Sedge, is a dry site specialist that needs very little soil to grow. Growing only 11 inches tall, Ivory Sedge grows naturally in limestone rocks in partial shade, and is extremely drought tolerant-staying green all summer long. Pennsylvania Sedge is a popular fine-textured sedge that creeps by rhizomes; this sedge forms a unique “lawn-like” appearance that will grow in shade to part sun. Plantain Leaved Sedge is quite unusual, with wide leaves that shine almost neon-lime green, it grows in part sun to shade, thriving in alkaline soils, or clay soils – and even in rocky limestone and dolomite rocks!

Often under utilized, sedges provide unique textures paired with wildflowers and grasses. Because sedges green up earlier than other prairie grasses, they can be amazing companions, or matrixes for spring bloomers such as Prairie Spiderwort, Lanceleaf Coreopsis, Wild Geranium, and Columbine. In low moist areas, try the Palm Sedge with Bottle Gentian, Boneset, Common Bluestar and Marsh Phlox. Don’t forget their use in rain gardens: helping to slow rain water and filter the moisture slowly into the soil, improving soil quality, and attracting a multitude of beneficial insects and birds that will enjoy the seed.

Give sedges a try in your landscape!