With its sea of striking cool silver-blue, Carnation-like foliage, this dense,
clump-forming Carex creates a noninvasive,
slowly spreading mound of unusual and attractive foliage. The gentle flower spikes that float like a subtle mist above the stems in late spring / early summer are neither showy nor detract from the clean look of this plant.
Carex flacca leaves are narrow 3/16 inch wide leaves, blue-green on the upper surface and
glaucous gray-blue beneath (with the overall look being quite blue), 6-10 inches in height. Evergreen in warmer climates.
Often massed near ponds or streams, it helps combat
soil erosion. With regular watering, it can be used for a ground cover, naturalizing, as
edging, and in rock gardens and containers. If used directly in a water garden, it can be planted up to 2" below the water surface.
Easy to establish and a versatile,
low ground cover, Carex flacca adapts to most growing conditions and is easily grown in average, medium to wet well-drained soil in
full sun to
part shade. It does best in constantly
moist, fertile soil, but once established is more tolerant of
drying out than many of the other Carex species.
Tolerant of light
foot traffic, it spreads
slowly by
rhizomes which can be encouraged by trimming back lightly: a mowing set at 4 inches high in early spring (and perhaps once or twice more each year) keeps this plant vigorous and creates a more manicured, tidy appearance. It competes well with shallow tree roots and spreads much more quickly with ample water and
fertilizer. Clumps are easily divided in spring or early fall.
Interesting Fact This plant is from the area around the Mediterranean Sea where it grows in
calcareous grasslands, sand dunes and in estuaries in Europe and North Africa, it has naturalized in eastern North America.
This plant has long been offered in the US as Carex glauca, however the correct name is Carex flacca. The name Carex flacca is not a name change but the confusion between these two names for the same plant has been going on a long time. The Department of Botany of the British Museum first discusses this in their 1898 report and cites the reason why the name C. flacca takes precedence. Carex flacca was described by German botanist and zoologist Johan Christian Daniel von Schreber in 1771 and a year later Giovanni Scopoli, an Italian physician and naturalist, described a plant he called Carex glauca. Once it was determined that these plants were the same species, the older name should have taken precedence but apparently Carex flacca, the older name, was at first overlooked and Carex glauca came into more common usage.