Scott Woodbury
When most gardeners think of sedges, a particular weed comes to mind. Yellow nutsedge. It isn't a proper sedge in teh genus Carex, but a flatsedge in the genus Cyperus which mostly consists of spreading species too weedy for gardening. Among Carex, however, several work well in the garden. Unlike their flatsedge cousin, these garden-worthy species delight gardeners. For real, as my 5-year-old son would say. Take cedar sedge, Carex eburnea, for instance. Its pocket-sized emerald green tufts of hair-like leaves top out at 3 inches. This winter it was nearly evergreen, though in normal years it turns tan. It slowly creeps to form into a dense mat in dry, shady places and works nicely with other diminutive shade-lovers like wild sweet William, Phlox divaricata and crested iris, Iris cristata. There is an interesting YouTube video of this one showing the plant in the wild.
Next in the line of tiny sedges is bristle sedge, Carex leptalea. It is also referred to as slender sedge or bristle-stalked sedge. IT looks like a green bristle brush or a spiny sea urchin. Slow-growing and topping off at 4 inches, this one is similar to cedar sedge though it tolerates sun and wet areas. It makes an ideal rain garden plant at the edges. In the Whitmire Wildflower Garden, where I've gardened for the past two decades, this one grows next to prairie alumroot, Heuchera richardonii, and is partially shaded by a red buckeye, Aesculus pavia, which blooms at the same time in early April. Bristle sedge is currently in production at the Shaw Nature Reserve and should become available in 2013 at the Spring Wildflower Sale.
Oak sedge, Carex albicans, is gaining popularity thanks to its ease in gardening and the pioneering work of Missouri Wildflowers Nursery. It is a shade to part sun-loving sedge growing 8-10 inches on dry to moist soils. Its arching thread-like foliage surrounded by prairie pussytoes is a winning combination. If you like this one, you might try the very similar James sedge, Carex jamesii, which is slightly evergreen though its leaf tips tend to go tan in summer.
A versatile Carex that would grow in most gardens is palm sedge, Carex muskingumensis. It tolerates sun or shade, dry or wet. Beginner gardeners can't go wrong with this one. It's two feet tall, long-lived and provides a fine-textured tropical contrast to broad-leaved plants. In sunny areas mix in a couple yellow wild indigo, Baptisia sphaerocarpa and orange coneflower, Rudbeckia fulgida. In the shade, try it with sensitive fern, Onoclea sensibilis and the bold round leaves of wild hydrangea, Hydrangea arborescens. It also tolerates rain gardens and tough clay. When planted in mass, palm sedge reduces garden maintenance. It can be cut down once a year in March with a push mower set on high with no need to rake up clippings or for mulching. Two other terrific sedges under two feet for shade include fringed sedge, Carex crinita, and bur sedge, Carex grayii.
If you are looking for a low-maintenance native groundcover to use instead of invasive wintercreeper, English ivy, periwinkle or liriope, look no further. Gold sedge, Carex aureolensis, at 10 inches, is a great alternative. Tolerant of sun and shade, t his creeping sedge quickly fills into a solid mat, eliminating most weeds and the need to mulch. Simply mow in March as you would, liriope and walk away. Scatter in a few companion plants like seedbox, Ludwigia alternifolia, or slender mountain mint, Pycnanthemum tenuifolium, for contrast. Brown sedge, Carex buxbaumii, and field sedge, Carex praegracilis, are two other top-performing alternative groundcovers.