Sometimes known as chufa (sedge), nut grass, water grass, and others, it is a fast-growing upright plant. It is that rapid growth along with its lighter, almost lime green color that calls attention to itself in the lawn and landscape.
Yellow nutsedge is a perennial, sprouting most often from underground tubers called nutlets. Rhizomes are also formed and can give rise to singular plants.
Frost can kill the above ground portion, but nutlets will produce new plants in the spring. These nutlets can survive in the soil for more than three years. The plant easily withstands mowing pressure, however it will grow up to three feet in non-maintained areas.
Nutsedges will produce a spikey seedhead, but seeds rarely germinate. The plant prefers low lying, wet soils or areas that are frequently watered, however it can show up just about anywhere.
Yellow nutsedge displays some features that are easy to identify. For one, unlike grasses which are rolled or folded in the shoot, yellow nutsedge is triangular. You can easily distinguish this by rolling the stem between your thumb and index finger. Otherwise, look for leaves grouped in threes, a prominent midvein, and a waxy/shiny coating.
Controls start with encouraging a dense turf cover and improving surface drainage, but once established, you will continue to see a problem.
The above-mentioned waxy cuticle along with the upright growth habit are two major factors in the difficulty of control. Most liquid herbicides depend on foliar absorption for control which can be tough in this situation, particularly if a surfactant is not used. Oftentimes successive applications will be required, and several materials are slow acting, giving the feeling that nothing is happening. Many of the control products are somewhat pricey and typically used as spot applications.
Chemical controls include:
• Sodium Bentazon (Basagran) – This photosynthetic inhibitor has some tradition in the industry. It must be mixed with a crop oil and may require a second application within 7 to 10 days in northern regions or repeat sprays in the south where yellow nutsedge can persist year-round. Safe for use on MOST turfgrasses and in ornamental beds.
• Halosulfuron (SedgeHammer, Prosedge, sedgemaster) – An ALS inhibitor that also has some industry history. A non-ionic surfactant is recommended unless using the SedgeHammer+ formulation which already contains an NIS. Repeat applications may be required in 6- to 10-week intervals depending on the size when initially treated. Most grasses are tolerant, and it can be used in landscape areas.
• Sulfentrazone (Dismiss products, Expel or in combination herbicides Q4Plus, Surge, TZone and many others) - A PPO inhibitor. Combination products labeled for suppression may require repeat applications due to lower AI load. Solitare has a full sulfentrazone load and shouldn’t require a re-application. Dismiss does not require a surfactant. Sulfentrazone will be the quickest in response time. Most grasses are tolerant, but certain species of Tall Fescue, Fine Fescues, St. Augustine, Zoysia, and Bahia may exhibit some level of injury. Sulfentrazone is primarily root absorbed and is almost solely a turf label.
• Mesotrione (Tenacity) – An HPPD inhibitor. Good for post-emergent control in most cool season grasses except bentgrass. An NIS will enhance performance and usually two applications will be necessary about two weeks apart. First signs of control will be the typical bleaching look. Although preemergence is not listed on the label, some activity has been witnessed.
• Pyrimisulfan (Vexis) – The new kid on the block. A granular ALS inhibitor. Labeled for use on cool and warm season grasses. Requires irrigation within 48 hours.
A few products tout pre-emergent control, most of which are labeled for suppression. Those products contain dimethenamid-p (Tower and Freehand) or S-Metolachlor (Pennant Magnum).
One last tip! Make sure that early application is part of your strategy. Plants will put on nutlets as summer sets in, making regeneration much more likely. Controlling them in younger stages prevents this.
As always, read and understand labels before using these products. And let us know if there are any questions.