The genus Carex is among our largest groups of native plants in most of temperate North America. This diversity creates abundant opportunities for undiscovered species of ornamental potential, particularly for use as groundcovers or mass plantings. An extremely adaptable species for this purpose is meadow sedge (Carex granularis).
This reliable plant thrives in a variety of moisture levels from saturated to mesic, and in light conditions ranging from filtered shade to full sun. Native to much of the eastern half of the United States, it was first collected and named by a botanist in the early 1800s. The natural range of Carex granularis extends from New Brunswick in eastern Canada west to Manitoba and south to Louisiana and Florida. Based on this range, it should be hardy from zones 3 to 9.
The broad, bluish-green foliage is semi-evergreen, experiencing tip dieback when temperatures dip to subfreezing levels in late fall. New foliage begins to appear early in April here in central Indiana (Zone 6). By early May, several inconspicuous inflorescences emerge from the base of the clump. These reach 8 to 10 inches in length before flopping over as the seed matures in mid- to late June. The foliage spreads horizontally to create a clump about 1 foot in diameter and 6 inches high, remaining fresh and attractive throughout the growing season until hard freezes brown the tips.
The adaptability of this sedge to varying moisture and exposure makes it an excellent species to use for mass plantings as a groundcover; it is especially useful for landscape beds under trees. It is suitable for wet to medium soils; exceptionally droughty soils should be avoided. The plant prefers a neutral soil with a pH between 6.5 and 7.5. Areas with acid soils will benefit from the addition of lime to the planting beds.
This species performs best in partial shade. It will also grow well in full sun if soil moisture is adequate. Some burning of foliage may occur if soil moisture drops very low in sunny sites. Dense, dry shade should be avoided.
Due to its tolerance of wet or well-drained soils, Carex granularis is an excellent plant for use in stormwater infiltration practices, such as rain gardens and bioretention basins. In these practices, it will tolerate inundation for periods of up to 24 hours after a storm event. Areas that take longer than 24 hours to drain, or those that pond deeper than 4 to 6 inches, should be avoided. Due to its low growth habit, it is an excellent species to utilize as an edging along the borders of these sites. Appropriate native companions in a rain garden include blue mist flower (Eupatorium coelestinum), bottle gentian (Gentiana andrewsii) and golden Alexanders (Zizia aurea).
Annual maintenance is minimal, consisting of cutting and raking the old foliage to a height of 3 inches in late winter. This may be effectively accomplished with a bagging lawn mower.
Carex granularis represents another fine contribution to horticulture from our native sedges. As a mass planting, its adaptability to varying soil moisture and light conditions makes it an excellent species for a variety of situations. It forms an attractive, low groundcover when planted on 10-inch centers. It has been largely free of pests and diseases here in central Indiana, although rabbits and voles occasionally dine on the foliage and new shoots.
Restoration Ecologist, Spence Restoration Nursery