FIRST IMPRESSIONS: Carex sprengelii is a lovely cool season woodland sedge. Plants form small colonies from short rhizomes. Foliage is bright green to chartreuse and semi-evergreen with narrow glossy blades. In early spring greenish-white or pale yellow spikelets are held above the leaves. Pendulous green to brown seedheads with long beaks follow. In the wild, this sedge occurs in partial sun or shade in moist or wet woodlands. In landscape situations, Carex sprengelii is an excellent groundcover or accent.
HABITAT & HARDINESS: Carex sprengelii is native in Alaska and the southern Canadian provinces south to Delaware and west to Montana, Wyoming, Colorado and New Mexico.
Plants are indigenous to dry to mesic deciduous forests, mixed conifer-hardwood forests, floodplain forests, river banks, shores of lakes and creeks, limestone river bluffs, meadows, thickets and roadsides. This species is usually associated with calcareous soils and rocks.
Carex sprengelii is hardy from USDA Zones 3-5.
PLANT DESCRIPTION: Carex sprengelii forms loose leafy tufts. Plants slowly spread into small open stands from short underground rhizomes.
Foliage is fine textured and bright green. Blades are up to 30” long and about 1/8” wide. The narrow glossy leaves are semi-evergreen through most of the range.
In early spring fertile culms with brown fibrous bases rise above the foliage. Each of these stems bears 1-4 staminate spikelets toward the tip. These ¾” long spikelets are very showy because of their creamy yellow stamens.
The culms also bear 4-5 widely spaced pistillate spikelets below the staminate spikelets. The pistillate spikelets are cylindrical with slender stalks and about 1 ¼” long. The pistillate spikelets are green with curly white styles.
By early summer, each pistillate spikelet matures into seed clusters with 10-40 long beaked perigynia. The perigynia are spherical, ribbed and shiny with a single achene inside. They are golden green gradually turning darker brown.
This sedge is about 1-3’ tall with a 2’ spread.
CULTURAL & MAINTENANCE NEEDS: Carex sprengelii is a sedge for sun or part sun and moist or wet soil.
Plants prosper in dappled sunlight, part shade, alkaline pH, sand, loam and clay. Moist soil is preferred but plants will tolerate average soils and some drought.
This sedge is pest resistant and unpalatable to deer and other herbivores.
In gardens, groundcover plantings can be cut to the ground during late winter to make way for fresh new growth.
LANDSCAPE USES: Carex sprengelii is an attractive Groundcover or Edging Plant. This sedge is lovely when planted in a soothing Grouping or Mass. Plants provide Erosion Control and Winter Interest and are appropriate for Deer Resistant Plantings, Low Maintenance Plantings, Shade Gardens, Water-wise Landscapes and Wildlife Gardens.
This species has particularly showy flowers and fruit and is able to thrive in difficult dry shaded sites.
COMPANION & UNDERSTUDY PLANTS: Try pairing Carex sprengelii with Asclepias incarnata, Aster puniceus, Eupatorium perfoliatum, Iris versicolor, Iris virginica, Juncus effusus or Lobelia cardinalis.
Carex pensylvanica has similar cultural needs and can be substituted in some situations.
TRIVIA: Carex sprengelii can be differentiated from similar species due to its drooping seed spikelets, round vein-less perigynia, long slender perignia beaks and very fibrous culm base.
This sedge provides cover for birds and other wildlife. Small mammals and birds forage or the seed.