Turf - Controlling Nutsedge

The following is information on controlling Nutsedge in Turf.

Control options for the homeowner are rather limited; look for products with the active ingredient sulfentrazone or halosulfuron. Yellow nutsedge control options for professional applicators include Dismiss (sulfentrazone) and Sedgehammer (a.i. halosulfuron). Repeat applications will likely be required to achieve control. As with any herbicide applications at this time of year, be cautious of applications to turfgrass that is under drought or heat stress, even with the relatively cool temperatures, the soil is drying out in many areas and the turf is starting to show some stress. General recommendations are to avoid herbicide applications when temperatures are above 80 F due to the risk of burning the turf. Sulfentrazone has been implicated in causing damage to tall fescue turf in some cases, especially when applied with urea fertilizers.

Information in part from the Michigan State University Landscape Alert Site http://ipmnews.msu.edu/landscape/

Landscape and Turf - June Weed Notes

The following are some notes that I made for weed control in landscapes and turf areas in June.

• If you have not done so already, apply the second application of preemergence crabgrass herbicide (such as pendamethalin) to turf with a crabgrass problem. There may already be crabgrass breaks with all the wet weather and a postemergence material will be necessary in that case (such as fenoxaprop or quinclorac).
• Wet weather will promote yellow nutsedge growth. Postemergence herbicides with activity on nutsedge include halsulfuron , sulfentrazone , and bentazon. All 3 can be used in turf; halsulfuron and bentazon can be used around some landscape plants (check the label). Glyphosate and glufosinate can be used as a directed, wiper, or spot spray application in landscapes. Two applications are often needed with bentazon, glyphosate, or glufosinate for effective nutsedge control.
• Summer annual weed escapes in landscape beds will be evident. Hand weeding is often the only option. Directed applications of glyphosate, glufosinate, or pelargonic acid herbicides can be used where there is space between desirable plants. Post emergence grass herbicides (fenoxaprop, clethodim, fluazifop-P-butyl, and sethoxydim) can be used over the top of many landscape plants where annual grass weeds are dominant.

Gordon Johnson, Extension Horticulture Agent, UD, Kent County

Landscape and Turf - Revisiting Nutsedge Control

The following is a repost of an article that I wrote on nutsedge control in turf and landscapes. Wet weather will increase infestations of this weed.

Yellow nutsedge (Cyperus esculentus) is a troublesome sedge weed in turf and landscape beds, particularly in irrigated and wetter areas. Heavier nutsege infestations will occur in wet years. It has shiny, yellow-green grass-like leaves, a triangular stem (characteristic of sedges as a group) and, if kept un-mowed, will produce a yellow-brown seed head cluster. It spreads by rhizomes and produces tubers that are formed at the end of these rhizomes. One plant can produce up to 700 tubers in a season. Tubers have buds that will send out new shoots following a dormancy period (cold required). Tuber sprouting is promoted by high soil moisture conditions. Viable seeds may also be produced. Yellow nutsedge tolerates light shade and medium mowing heights. It can grow through plastic mulch and may come through landscape fabric. Nutsedge is often introduced into a landscape through tuber infested soils carried with planting material (such as B&B plants).

Control of established patches of yellow nutsedge can be difficult. Hand digging is ineffective unless all tubers are removed from the soil. Tillage and hoeing often promotes nutsedge spread by moving tubers around and cutting tubers that will result in multiple plants being produced. Mulch can suppress nutsedge; however some nutsedge plants can grow through the mulch. Moisture control (keeping areas dry) will limit nutsedge emergence but will not work in irrigated areas. Fortunately, there are several herbicides that are effective on nutsedge. Metolachlor applied preemergence has provided good control in landscape beds. Halsulfuron applied post emergence has provided excellent control in established woody landscape plantings and in turf. Sulfentrazone gives excellent post emergence yellow nutsedge control in turf and is effective against many other sedges (annual and perennial) such as Kyllinga. Bentazon can be used over the top for nutsedge control in established turf and some ornamentals and as a directed spray in most landscape situations. Two applications are generally needed for best control. Glyphosate (directed, wiper, or spot spray applications) can also control nutsedge; however 2 or more applications are often needed.

Gordon Johnson, Extension Horticulture Agent, UD, Kent County

Turf and Landscape - Nutsedge Control

Yellow nutsedge (Cyperus esculentus) is a troublesome sedge weed in turf and landscape beds, particularly in irrigated and wetter areas. We are seeing more nutsedge this year after the wet May and wet periods in June. The following is information on nutsedge and nutsedge control.

Nutsedge has shiny, yellow-green grass-like leaves, a triangular stem (characteristic of sedges as a group) and, if kept un-mowed, will produce a yellow-brown seed head cluster. It spreads by rhizomes and produces tubers that are formed at the end of these rhizomes. One plant can produce up to 700 tubers in a season. Tubers have buds that will send out new shoots following a dormancy period (cold required). Tuber sprouting is promoted by high soil moisture conditions. Viable seeds may also be produced. Yellow nutsedge tolerates light shade and medium mowing heights. It can grow through plastic mulch and may come through landscape fabric. Nutsedge is often introduced into a landscape through tuber infested soils carried with planting material (such as B&B plants).

Control of established patches of yellow nutsedge can be difficult. Hand digging is ineffective unless all tubers are removed from the soil. Tillage and hoeing often promotes nutsedge spread by moving tubers around and cutting tubers that will result in multiple plants being produced. Mulch can suppress nutsedge; however some nutsedge plants can grow through the mulch. Moisture control (keeping areas dry) will limit nutsedge emergence but will not work in irrigated areas. Fortunately, there are several herbicides that are effective on nutsedge. Metolachlor (Pennant Magnum) applied preemergence has provided good control in landscape beds. Halsulfuron (Sedgehammer) applied post emergence has provided excellent control in established woody landscape plantings and in turf. Sulfentrazone (Dismiss and several combination products) gives excellent post emergence yellow nutsedge control in turf and is effective against many other sedges (annual and perennial) such as Kyllinga. There is some concern with using sulfentrazone on tall fescue as injury has been found when applied with fertilizers. Bentazon (Basagran T/O) can be used over the top for nutsedge control in established turf and some ornamentals and as a directed spray in most landscape situations. Two applications are generally needed for best control. Glyphosate (directed, wiper, or spot spray applications) can also control nutsedge; however 2 or more applications are often needed.

Gordon Johnson, Extension Horticulture Agent, UD, Kent County

Turf - Herbicide Products for Yellow Nutsedge Control

Yellow nutsedge can be a problem weed in turf. The following are some slides on newer nutsedge control products that are available for use in turf.

Click on Slides for a Larger Image

Slides from a presentation by Dr. Steve Hart, Rutgers University.

Ornamentals Hotline Weed Pictures for Issue 19, August 3, 2007

White clover, an indicator of low mowing height and low fertility soil.

Spurge, an indicator of compacted soil.

Prostrate knotweed, an indicator of compaction.

Red Sorrel, an indicator of low pH, low fertility soil or dry soil.

Plantain, an indicator of low fertility soil.

Nutsedge and Oxalis (woodsorrel), indicators of wet soil.

Nimblewill, an indicator of excess shade.

Goosegrass, an indicator of compacted soil.

Crabgrass, an indicator of low mower height, wet soils, or high fertility.

Carpetweed, an indicator of dry soil.

Black Medic, an indicator of dry soil.

Bermudagrass (wiregrass), an indicator of low mowing height, compaction, or high fertility.

All Weed Pictures by Gordon Johnson, Extension Agent, Agriculture and Commercial Horticulture, University of Delaware, Kent County

Ornamentals Hotline Weed Pictures for Issue 17, July 20, 2007

Yellow Nutsedge Plants

Yellow Nutsedge in Turf Near Drain Outlet

Yellow Nutsedge Growing Through Mulch


Yellow Nutsedge Rhizomes


Glyphosate Spot Sprayed on Yellow Nutsedge: Multiple Applications Will Be Needed


Newly Forming Tubers at the End of Rhizomes on Yellow Nutsedge (magnified 8x)

Mature Tuber From Yellow Nutsedge (magnified 8x)

Triangular Stem of Yellow Nutsedge (Magnified 8x)

All Yellow Nutsedge Pictures by Gordon Johnson, Extension Agriculture and Commercial Horticulture Agent, University of Delaware, Kent County