Barbara J. Bromley, Mercer Co. Horticulturist
Yellow nutsedge (Cyperus esculentus), a perennial, is a grass-like sedge that can infest lawns and landscape beds in warm weather. In one growing season a few plants may be replaced by large patches of the pest.
DESCRIPTION: Yellow nutsedge is grass-like in appearance and can be distinguished from grasses by rolling a piece of stem between the thumb and forefinger. Nutsedges have triangular shaped stems, while grass stems are usually hollow and rounded or flat. Nutsedge leaves are v-shaped, appear folded lengthwise and are yellow-green. They grow faster than the surrounding turfgrasses in warm to hot weather. In landscape beds seeds are produced on a long, umbrella-shaped stalk in mid-summer. The plants spread by rhizomes and underground tubers, commonly called “nuts” or “nutlets.” The tubers can remain viable in the soil for two to four years.
GROWING CONDITIONS: Yellow nutsedge prefers warm to high temperatures, full sun, and a lot of moisture, although it can tolerate dry weather. It grows poorly in shade. Shoots from underground tubers begin to appear in June as soil temperatures rise. New tubers or nutlets are formed about 4 to 6 weeks later in warm soil and adequate moisture. Yellow nutsedge goes dormant early in fall.
CONTROL: CULTURAL Combining the, following cultural practices may help prevent or reduce: nutsedge infestation:
- Hand removal: Physically remove nutsedge plants by pulling them out every time they appear. Continue to pull each time they show up until the plant is spent because of lack of photosynthesis, (food production).
- Repair damaged areas: It’ areas of turf are thinned or damaged by insects or other problem, reseed or sod when conditions are right for seed to germinate or sod to knit. Bare areas are an open invitation for weed invasion.
- Improve drainage in low areas where water collects.
- Apply landscape fabric weed barrier in ornamental beds.
Yellow nutsedge may be control1ed chemically by one or more applications of the following materials. Products such a Finale and Roundup can also be used as a direct spray on individual plants, bur have the potential to injure ornamental plants and will kill turfgrass.
|Table 1: Postemergence Controls for Nutsedge in Cool-season Turfgrasses|
|Trade Name||Common Name||Comments|
|DSMA, MSMA, CAMA, AMA||organic methanearsonates||Effective when sprayed on young plants and repeated in 10-14 days..Apply at rate for mature crabgrass. Turf injury or temporary discoloration (yellowing) may occur. Use when turf is in good growing condition and is not under heat or drought stress. Must he reapplied several times each year for two to three years.|
|BASAGRAN||bentazon||Contact herbicide with a small amount of translocation. Probably need 2 applications 10-14 days apart. Do not mow 3-5 days before or after treatment. Do not apply to new seedings until grass is well established. Best applied in July. Include a drop of oil to increase activity. Works on a wide range of established turfgrasses. Perennial rye may be more sensitive.|
|MANAGE||halosulfuron||Systemic herbicide with both pre- and post-emergence activity against nutsedge. Works better post-emergence. Provides about a month of residual activity. One application could be enough, but may require a sequential application 6-10 weeks after the first. Add a nonionic surfactant for optimum results.|
|Table 2: Preemergence Controls for Nutsedge in Ornamental Beds|
|Trade Name||Common Name||Comments|
|PENNANT||metolachlor||Only material labeled for preemergence control of yel!ow nutsedge. Do not allow movement into turfgrasses as injury may result. Apply prior to May 10. May need second application since Pennant provides only 2-3 months residual activity.|
|CASORON, NOROSAC, DYCLOMEC||dichlobenil||Can be used in certain established woody ornamentals. Volatile under warm conditions.|
|DEVRINOL||napropamide||Provides some suppression of nutsedge, especially under mulch.|
For more information about home grounds weed control, see Rutgers fact sheet FS 119.Mention of a trademark, proprietary product, or firm in text or figures does not constitute an endorsement by the U.S. Department of Agriculture and does not imply approval to the exclusion of other suitable products or firms.