Carex flacca
Common Name: blue green sedge 
Type: Rush or Sedge
Family: Cyperaceae
Native Range: Europe
Zone: 4 to 9
Height: 0.50 to 1.00 feet
Spread: 1.00 to 1.50 feet
Bloom Time: June to July
Bloom Description: Light green
Sun: Full sun to part shade
Water: Medium to wet
Maintenance: Low
Suggested Use: Ground Cover, Naturalize, Rain Garden
Flower: Insignificant
Leaf: Colorful
Tolerate: Deer, Drought, Erosion, Wet Soil


Easily grown in medium to wet soils in part shade to full shade. Thrives in moist soils, including standing water to 1-2” deep, but established plants also perform well in average garden soils with some moderate tolerance for drought. Will grow in full sun in cool summer climates. Evergreen in warm winter climates, but foliage should be cut to the ground and removed in late winter in cold winter climates.

Noteworthy Characteristics

Carex flacca, commonly called blue-green sedge, is a dense, cool-season, clump-forming but slowly creeping, grass-like, rhizomatous, evergreen sedge which typically grows to 6-10” tall and features narrow, arching, somewhat coarse leaves (3/16” wide) which are blue-green above but blue-gray beneath. It is native to areas around the Mediterranean where it typically grows in calcareous grasslands, marshes, sand dunes, and estuaries in southern Europe and North Africa. It is primarily grown in landscapes as a ground cover for its foliage effect. Insignificant flowers appear in early summer on terminal, cylindrical spikes to 12” tall. Plants spread somewhat slowly, but will form colonies after several years and can be used as an effective ground cover. Tolerates very light foot traffic.

Carex flacca was first described by German botanist Johan Christian Daniel von Schreber (1739-1810) in 1771. One year later, the same plant was described by Giovanni Scopoli (1723-1788), Italian physician and naturalist, as Carex glauca. Carex glauca is now generally recognized to be simply a synonym of Carex flacca. Under the “first in time” rule, Carex flacca is the accepted botanical name for this species.

Genus name from Latin means cutter in reference to the sharp leaves and stem edges (rushes are round but sedges have edges) found on most species' plants.

Specific epithet means weak or soft.


No significant insect or disease problems.


Mass or group in woodland gardens, shade gardens, borders or rock gardens. Effective accent for smaller gardens. Ground cover for shade gardens. Edging plant for paths or walkways. Also appropriate for areas with moist soils such as low spots, stream/pond margins or bog gardens. Grows in standing water to 2” deep in water gardens.