Nutsedge is a challenging type of grassy weed that can be found in turf and landscapes all across the country. Also known as nutgrass, they are perennial weeds that superficially resemble desired grass. They are considered one of the most problematic weeds of agriculture in temperate and tropical regions of the world. They can form dense growth clusters known as colonies that can reduce crop yields by a substantial amount. The two main types of nutsedge are yellow nutsedge, known by its scientific name of Cyperus esculentus, and purple nutsedge whose scientific name is Cyperus rotundus. They tend to grow rapidly in the heat of summer when grass growth slows.
Nutsedge is particularly challenging because of its resemblance to desired turfgrass growth in lawns and landscapes. As nutsedge matures it becomes easier to identify as the stems of nutsedge are triangular in shape. Leaves have a distinctive rib down the center and produce a “v” shape. The bright yellow-green leaves distinguish it from regular turf as it will stand out against the deeper green colors of healthy grass. If left to grow tall, both purple and yellow nutsedges produce spiky flower clusters. Stems are erect and hairless, and lack collars, ligules, and auricles like desired grass leaves have.
Outbreaks of a nutsedge colony usually form in moist and poorly drained soil conditions. The yellow variety of nutsedge is found in temperate climates around the world including Europe and Africa. Every state in the United States have invasions of nutsedge with the exception of Montana and Wyoming. Purple nutsedge doesn’t grow quite as well in dry climates, but it is extremely prevalent around the southeastern United States, Gulf states, California, and Arizona. It is reportedly native to India but has spread to most countries around the world. Disturbed areas and lawns with moist soil provide the ultimate conditions for purple nutsedge to grow.
One of the reasons why nutsedges are so difficult to control is because of the way it reproduces. It not only produces by seeds and rhizomes, but it also reproduces by underground nodules known as nutlets. Once it has become established in a colony, it can survive almost any soil conditions. They are a perennial weed, lasting at least two years if left to grow without control measures. Even though this invasive weed may be the bane of the existence of lawns and gardens, it has one redeeming factor – it is edible and is sometimes referred to as Earth Almond or Chufa.
Post-emergent herbicides labeled for use on nutsedge is one the best means of controlling established nutsedge in lawns. Pre-emergent weed control treatments are key for keeping nutsedge off lawns. You can also protect against nutsedge infestations by practicing good lawn care basics. Healthy and well-established turf is an excellent defense against nutsedge establishment in lawns. Year-round weed control is needed to keep this weed at bay.