Nutsedge and nutgrass are common weeds that favor warm climates and poorly drained or over-irrigated areas. Golf courses often provide ideal environments for them. Some of the more common sedges on golf courses include purple nutsedge, yellow nutsedge, globe sedge, rice flat sedge, annual sedge and the kyllinga species.(pronounced kuh-LING-guh)
Nutgrass
Most everyone in Southeast Texas is fairly familiar with nutsedge, the thin-bladed weed that I like to think of as monkey grass on Quaaludes. Nutgrass can have the little seed rhizomes (nuts) as deep as 18 inches underground and can sit dormant for nine years. You can pull it, but you're leaving the nuts in the ground. That's why pulling is bad. The herbicides below work really well, but they can take up to two weeks to produce results.
There are two other forms of nutsedge that are harder to identify. One is the uber-thin sedge that almost always sets up shop in the wettest of areas. And I get lots of calls and emails about a sedge that has the burrs on top … kyllinga. As the name implies, it should be kylled.
Kyllinga species are becoming more prevalent on golf courses. Forty-five varieties exist in the world, but only five are found in the continental U.S. And there’s one found in Hawaii. Most are rather difficult to detect in turfgrass because they closely resemble the turf. Kyllinga leaves, however, are glossier than grass and are detected easier in the morning as dew falls off their leaves but remains on the turf. Also, kyllinga has a distinctive minty sweet scent when the leaves are mowed or crushed.
Green kyllinga produces seed throughout the growing season and is commonly misidentified as burrgrass. It is not. And because it’s a sedge, typical burrgrass herbicides won’t affect it at all. Kyllinga seed heads are about the size of a garden pea when un-mowed and have a light green color. Seeds start germination in spring and continue throughout the summer.
So, if you have it, you want to kill it, right? That’s where post-emergent controls specifically designed for nutrgass and kyllinga come in to play.
The Four Most Popular Brands of Nutgrass Control
- Sedgehammer by Gowan
- Nutgrass ‘Nihilator by Monterey
- Sedge Ender by Bonide
- Image by Lily Miller
I recommend Sedgehammer because it can be used at any time of the year. Sedge Ender is the most readily available sulfentrazone-based control. Nutgrass ‘Nihilator works well and is not sulfentrazone-based, but isn’t readily available in this area. And while Image used to be the go-to product for nutgrass, it has been shown to damage many St. Augustine lawns. Turns out that it is not safe to use when temperatures are 90 and above. And, when temperatures reach 50 and below, Image is more damaging to the lawn than to the weed. Bottom line: Image has a very small window for use - March, April and May
The key to success with any nutgrass control is to use a surfactant. Some of those here do not include any, so do a test run. Spray a test patch to see if the liquid actually adheres to the slick leaf surface. If it runs straight off, add a surfactant. Learn all about them here.
There is also an organic method to treat for nutgrass, but it’s very hit-and-miss. I’ve heard as many “it didn’t work” stories as I have successes, using molasses as a nutgrass control. Usually, you mix ½ cup of agricultural molasses with one gallon of water. Here too, I would add a bit of surfactant to the mix. Note that while you may still see the nutgrass blades, the molasses really does work on the “nut” part of the weed.
Pre-emergent two-in-one herbicides, like Barricade or Dimension, are also very hit-and-miss in controlling nutgrasses and nutsedges. So, early detection and early treatment is always the best way to control this annoying weed. Don’t ignore them when you first see them.