Controlling Pesky Nutsedge Requires Multifaceted Effort

— Written By and last updated by Diane Lynch

Q: How do I control nutsedge?

A: Nutsedge is one of those pesky weeds that seems to show up everywhere and never goes away. Nutsedge, also called nutgrass, is a perennial whose leaves die back in the fall and re-sprout in the spring from tubers (“nutlets”) and rhizomes (underground stems) in the soil. It is important to know that nutsedge is a sedge and not a grass because most herbicides for grass control are not effective on sedges. Nutsedge can be identified by looking at the stems. Grass stems are hollow and round, while sedges are triangular or V-shaped. The leaves of nutsedge are thicker and stiffer than most grasses and arranged in groups of three at the base. Unfortunately, nutsedge is not easy to eliminate. It will take a combination of cultural, mechanical, and chemical control over a long period of time to successfully control nutsedge.

Cultural Control: The ideal environment for nutsegde to start in is moist areas with poor drainage or frequent irrigation. Once nutsedge takes hold of an area, it can live in less moist areas and even in drought conditions. Proper lawn care is important in controlling nutsedge because a properly managed lawn will allow the grass to better compete against nutsedge by having less thin, bare spots. Proper lawn practices include mowing at ideal height, proper application of fertilizer and lime, proper irrigation, and having a soil test every 3-5 years to determine if the soil pH is ideal or needs adjusting.

Nutsedge is often accidentally brought into an area on plants, topsoil, sod, and equipment. Learning to identify nutsedge and being on the outlook for it when making purchases for the garden can prevent introducing it to your garden all together.

Mechanical Control: If you have a small patch of nutsedge, you can dig at least 10 inches deep and 8 to 10 inches beyond the infested area to reduce the amount of nutsedge. The dirt could be sifted to remove the “nutlets” or remove the soil from the area all together. Routinely weeding (every couple of weeks) can help reduce the amount of over time.

Chemical Control: Chemically controlling nutsedge depends on if it is located in a lawn, landscape, or vegetable garden. Herbicides labeled for nutsedge vary in their effectiveness. Note that nutsedge is a tough weed to control, and there is not a herbicide that will eliminate it with a single application.

For the lawn, the most common herbicide used is imazaquin (Image). Image has fair control on nutsedge and can be used on all types of warm-season grasses. Other herbicides include bentazon (Basagran) and halosulfuron (SedgeHammer).

For a landscape bed, caution should be used when using a herbicide for nutsedge. Some herbicides can injure foliage or roots of ornamental plants. Herbicides labeled for use in the landscape include: imazaquin (Image), bentazon (Basagran), and halosulfuron (SedgeHammer).

For vegetable gardens, chemical control of nutsedge is not as easy because you are dealing with edible plants. Spot treating with glysophate (Roundup) can be effective between rows. Carefully apply glysophate to prevent drift damage on vegetable plants.

Spring time, when it is actively growing, is the best time for attempting to control of nutsedge before more tubers are produced. Once nutsedge has more than five or six leaves, they begin to form new tubers underground, usually from May to June.

For your gardening, landscape, and lawn questions contact the Wayne County Extension Master Gardener Volunteer Plant Clinic on Mondays and Wednesdays from 10 a.m. to 1 p.m. The plant clinic is a free service open to any citizen in Wayne County that has home gardening questions. One can reach the Wayne County Extension Master Gardener Volunteer Plant Clinic by phone at 919-731-1433, e-mail at Master.Gardener@waynegov.com, or stopping by Room 100 of the Wayne County Extension Office (208 West Chestnut Street, Goldsboro). People contacting the plant clinic with questions are encouraged to bring samples and/or pictures that could help in reaching a solution. Extension Master Gardeners are trained volunteers with the Wayne County N.C. Cooperative Extension Service.

Recommendations for the use of chemicals are included in this article as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services does not imply endorsement by the North Carolina Cooperative Extension Service nor discriminated against similar products or services not mentioned. Individuals who use chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage and examine a current product label before applying any chemical. For assistance, contact an agent from North Carolina Cooperative Extension Service.

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Jessica Strickland
Extension Agent
Horticulture
North Carolina Cooperative Extension
Wayne County Center
P. O. Box 68
Goldsboro, NC 27533
E-Mail: jessica.strickland@waynegov.com
Phone: 919-731-1525
Fax: 919-731-1511
https://www.ces.ncsu.edu/wayne