Description:
Description and Variation: A fibrous-rooted perennial, yellow nutsedge has erect, triangular, yellow-green stems that grow 12 to 32 inches tall. Yellow nutsedge grows from perennial tuber-bearing rootstocks; the tubers are approximately 2/5 to 4/5 of an inch long. The leaves are narrow and grass-like, growing in three vertical rows on the stem. Most of the leaves are clustered at the base of the stem. The small flowers are yellowish or yellowish-brown, and arranged in narrow spikelets on umbel-like inflorescences (groups of flowers originating from a single point). Located immediately below the inflorescence are three to nine inch long leaf-like structures (bracts). The flowers have three stamens and a three-cleft style. The yellowish-brown seeds are about 1/16 inch long and three-angled (Muenscher 1955; Hitchcock et al. 1969; Torrell et al. 1993).

• Mechanical: Tillage at four week intervals will deplete the energy reserves of tubers. However, cultivation alone takes at least two years to eliminate yellow nutsedge (Lanini 1987). Cultivation should be carried out throughout the growing season, as long as tubers are sprouting. This strategy will ensure that no new tubers are formed. Fall cultivation, when tubers are dormant, is not an effective control method (Mulligan and Junkins 1976).
• Biological: The use of a biocontrol fungus is being investigated (Torrell et al. 1993).
• Herbicide: Yellow nutsedge control with herbicides is difficult because herbicide translocation is complicated by source-sink relationships within and between dormant tubers and germinating tubers and the shoot or growing plant. Most herbicides used affect only the shoots and/or roots and do not kill the tubers (Bayer 1987). Refer to the State Noxious Weed Control Board site

For More Information:
Detailed information about Yellow Nutsedge is available at the Washington State Noxious Weed Control Board Web Site.