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)
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.