Nutgrass is a perennial grass-like weed that is extremely hard to control in gardens and fields (not to mention flower beds). Infestations of this weed will start in the low parts of the field and then spread. It can grow anywhere.
Nutgrass will present yellowish green grass-like leaves and will appear to be a wide-bladed grass.
It is important to stress that nutgrass is not a grass but a sedge, despite the similarity.
Nutgrass (nutsedge) is a warm-season perennial weed with growth usually starting in the spring. Plants will grow from over-wintered tubers and nutlets germinating at the soil surface. The bulb will grow a fibrous root system and will produce rhizomes, secondary bulbs and nutlets at the end of the rhizomes.
Nutlet formation will begin in June and will continue through fall. One plant can produce hundreds to thousands of nutlets before the top of the plant dies in the fall. Each of the nutlets will grow a new plant, but not until they have gone through a chilling period. They can survive in the soil for years until they are exposed to the right growing conditions. Also, small seed heads can form from July to September and produce plants as well.
There is no "silver bullet" in fighting nutgrass. Nothing will eliminate it in one fell swoop. Control will need to be based on the use of a variety of methods to attack the weed. The most important single ingredient will be persistence. Rotate planting to eliminate nutgrass in an area before growing a crop there that is not labeled for herbicide use.
There are no herbicides that can be used to control nutgrass around cole crops, vine crops and strawberries.
A glyphosate product such as Roundup or Gramoxone (a restricted herbicide) will kill the tops of actively growing nutgrass in June and July before nutlets are formed. Post-emergent herbicides such as Poast and Fusilade will not work on nutgrass at all (remember this is not a grass). Pre-emergents may be of some help. The most common will be Dual at a two-pint rate. It is labeled for vegetable crops. For sweet corn, Aatrex can be used at higher rates or in combination with Dual, but be aware of recropping restrictions.
Gramoxone can be used as a direct spray on beans, vines, onions and some other crops. Dual II in combination with 2,4-D or Banvel can provide an effective burn down for sweet corn in a minimum tillage or no-tillage system. As with all herbicides it is a federal law to read and follow the label directions.
Good old-fashioned cultivation and hoeing are always options and can be effective.
EDDIE BAGGS, extension agent with the Texas AgriLife Extension Service in Denton County, can be reached at 940-349-2880.