Asiatic Sand Sedge, Japanese Sedge
(Carex kobomugi)
Biological Category
Plants
NY Legal Status
Not Regulated
Species Type
Grass-like Plant
DESCRIPTION
Asiatic sand sedge is a member of the Sedge family (Cyperaceae).
A robust, mat-forming perennial sedge, Asiatic sand sedge is rhizomatous, yellow-green in color, and has stiff, arching leaves. Growing four inches to, rarely, almost a foot tall, this species is most conspicuous when occurring as a mass.
Note: Research for these pages was generated from citations listed. References for specific statements available upon request.
Leaves: Leaves are stiff, sharply serrated, ‘V’ shaped in cross section and yellow-green in color. Stems are triangular in cross section.
Flowers: Flowers are arranged in short, dark brown spikes and emerge in early summer. These drab, upright inflorescences contain both male and female flowers.
Fruit/Seed: Seeds mature in summer and require scarification and a cold, moist period to germinate.
Accidentally introduced to the Pacific Northwest around the turn of the twentieth century, Asiatic sand sedge was intentionally planted as a sand dune stabilizer in the Northeast beginning in the 1960s. The species is now present in at least 8 states.
Asiatic sand sedge is an excellent competitor in beach habitat and is highly tolerant of salt spray, high winds and sandblasting. The species is commonly found on dunes in coastal areas, however, occurrences have also been found on lake and river shores.
Asiatic sand sedge reproduces both vegetatively and by seed. Populations in the species’ introduced range are theorized to be the result of a single genotype, arising from asexually produced seed or rhizome fragment dispersal during weather events or human activity. The deeply buried rhizomes of Asiatic sand sedge have a high number of internodes, allowing the species to spread very rapidly. Seeds are buoyant and appear to require scarification and possibly chilling. They are generally regarded as not having a very high rate of germination. However, up to 50% of seeds germinated when scarified and given a cold, moist period. Vectors include wind, water, and human activity.
Asiatic sand sedge is a fast growing, aggressive sedge species native to coastal China, Korea, and Japan. Extremely difficult to control due to an expansive, deeply buried network of rhizomes, the dense mats this sedge forms are capable of altering native species diversity and changing the dynamics of dune systems. Some studies suggest dunes colonized by Asiatic sand sedge make coastal habitats more vulnerable to erosion, while others suggest they stabilize dune systems too much, limiting the natural flux of this changing habitat. Furthermore, Asiatic sand sedge may directly threaten several endangered beach species including piping plover, beach tiger beetles and sea beach amaranth due to reduction of habitat and direct competition.
There is no biological control agent currently in use against this species.
Pulling / Digging Up: Pulling by hand is a time-consuming task and is only effective on small populations. Care must be taken to remove all below ground roots and rhizomes. Gloves are recommended.
Mowing: Not effective. Deeply buried rhizomes quickly re-sprout when above-ground material is cut.
Girdling: Not applicable
Prescribed Fire: No information available
Prescribed Grazing: Not applicable
Soil Tilling: Not advisable. Tilling will fragment roots and encourage re-sprouting.
Mulching: Not applicable
Solarization: Not applicable
Hot Foam Spray: Not applicable
The pesticide application rates and usage herein are recommendations based on research and interviews with land managers. When considering the use of pesticides, it is your responsibility to fully understand the laws, regulations and best practices required to apply pesticides in a responsible manner. At times, the pest you seek to treat may not be on a pesticide label, requiring a 2ee exemption from NYSDEC. Always thoroughly read the label of any pesticide and consult the NYSDEC or a licensed pesticide applicator with questions.
Foliar Spray: A 2-3% solution of glyphosate is effective at managing populations of Asiatic sand sedge. Repeat treatments are necessary at least twice a season to attain any measure of control. Follow up treatment will be necessary in subsequent years.
Cut Stump: Not applicable
Basal Bark: Not applicable
Stem Injection: Not applicable
Pre-Emergent Spray: Not applicable
General management overview and recommendation: As with any other invasive infestation, large occurrences of Asiatic sand sedge are best managed via a combination of mechanical and chemical means. Small seedlings or outlying plants can be hand pulled but care must be taken to remove all below-ground material. Dense patches must be sprayed at least twice a season to attain good control. All managed infestations should be monitored to prevent reinvasion from nearby populations. Any new occurrences can be hand pulled or sprayed.
Post treatment monitoring: Any infestations managed by chemical means must be revisited in 2-3 weeks to check for treatment efficacy. Follow up spot treatments will likely be necessary for at least one year after initial treatment.
Disposal Methods: All below-ground plant material must be bagged and disposed of in a landfill. Leaves may be composted so long as no viable seed heads are present on the plant.
United States Department of Agriculture
Ishikawa, S, A. Furukawa, T. Okuda and T. Oikawa. (1993)
Germination Requirements in Carex kobomugi. J. Plant Res. 106: 245-248