Nutsedges are aggressive and persistent weeds that commonly infest lawns, vegetable and flower gardens and landscapes. These perennial sedges are a problem in lawns because they grow faster than turfgrasses and result in non-uniform turf. In landscape beds, nutsedge can grow up through mulches–even plastic mulches!

Yellow nutsedge grows throughout California while purple nutsedge can be found mostly in the south of the state and the Central Valley. Once established, nutsedge is difficult to control because it forms tubers in the soil that can live up to three years. The best approach is to prevent the weed's establishment and spread.

Purple nutsedge. (Photo: Joseph DiTomaso)The two most common weedy species of nutsedge in California are yellow nutsedge, Cyperus esculentus, and purple nutsedge, C. rotundus. Yellow nutsedge grows throughout California, while purple nutsedge is more often found in the southern coastal and desert portions of the state as well as the Central Valley.

Although nutsedges resemble grasses and often are referred to as “nutgrass,” they aren't grasses but belong to the group of plants called sedges. Nutsedge leaves are thicker and stiffer than most grasses and are arranged in sets of three at their base while grass leaves grow across from each other in sets of two. Nutsedge stems are solid, and in cross section they are triangular; grass stems are hollow and round, and in cross section they are almost flat or oval.

Yellow nutsedge produces round, smooth, brown or black tubers that can be up to 7/16 inch (11 mm) wide at maturity. Only a single tuber forms at the end of a rhizome, and the tubers have a pleasant almond taste.

Red or red-brown scales cover purple nutsedge tubers. The tubers grow in chains with several tubers on a single rhizome, and they have a bitter taste. Purple nutsedge tubers are typically up to 1/2 inch (10-12 mm) wide but can be 7/16 to 1-1/3 inch (10 to 35mm) long.

The best approach for avoiding nutsedge problems is to prevent establishment of the weed in the first place. Once established, nutsedge plants are difficult to control.

To help you identify and better manage this troublesome weed, UC IPM has updated the Pest Notes: Nutsedge. This fact sheet was revised by UCCE San Diego Area Integrated Pest Management Advisor Emeritus, Cheryl Wilen. Updates include additional nonchemical control methods and herbicides that are effective for early nutsedge infestations.

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This article was first published in the UC IPM Pests in the Urban Landscape blog.