What Is Yellow Nutsedge?

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Yellow nutsedge is a specific type of nutsedge plant that is often viewed as a grass-like lawn weed when it appears in residential yards here in the Lincoln, Nebraska area. The true nature and classification of yellow nutsedge, however, is a bit more complicated. This aggressive and invasive plant is known to absorb all the water from a given area, leaving little moisture for your lawn and other plants. So, is yellow nutsedge a grassy weed, or is it something far more destructive that all homeowners in Nebraska need to know about? The Summit Lawns crew is here to clear it all up for you!


Sedges VS. Grassy Weeds

Nutsedge in lawn

The first thing you need to understand before identifying yellow nutsedge is that it is not a grass, nor is it a weed... it's a sedge! Though they are frequently viewed as grassy lawn weeds in the lawn care industry, sedges belong to an entirely different family of plants known as the Cyperaceae family (commonly called "sedge family"). Actual grassy weeds are simply undesirable grass types that belong to the Poaceae family (commonly called "grass family"), which is the same family that comprises the many different species of turfgrasses.

At the risk of making things even more complicated for you, yellow nutsedge is not even a "true sedge." Only sedges within the Carex genus are considered true sedges, and yellow nutsedge is a species of plant that belongs to the Cyperus genus. For a homeowner or lawn care enthusiast in Nebraska, however, you should always consider nutsedge to be one of the most invasive and aggressive grass-like weeds you will encounter. Thankfully, there are some quick and easy ways to differentiate yellow nutsedge from other types of weeds, which is the important first step in removing it from your yard before it's too late!

Identifying Yellow Nutsedge

Sedge Grass Weeds

Before yellow nutsedge matures and flowers, it can be difficult to identify this weed because of its similarities to turfgrass. In fact, nutsedge is commonly referred to as "nutgrass" or "watergrass" because it so closely resembles grass. When trying to spot yellow nutsedge in your lawn, look for dense, scattered clump-type growth. If your lawn has been invaded by nutsedge, clumps of the weed will likely start to spread out across your lawn, and they will grow faster, taller, and greener than the healthy turfgrass in your lawn. Yellow nutsedge is much easier to identify once the plant matures because of the yellow, thistle-like flower head developed by the weed, but this is a sign that a nutsedge invasion is already well underway.

The best way to identify nutsedge is not actually by sight! As a member of the sedge family, the stems of nutsedge feel different to the touch than those of healthy grass species. The stems of sedges are solid rather than hollow and do not include nodes, both of which are characteristics that differ from turfgrass. The most easily identifiable difference is the triangular shape of sedge stems. If you are ever unsure whether you are seeing yellow nutsedge among similar-looking grass, you can roll your fingers over the stem of the grass in question. If it is yellow nutsedge, you will feel three distinct edges that are not present on regular turfgrass.

Look For These In Your Lawn:

  • Taller, different-colored leaf blades than turfgrass
  • Leaf blades that are smoother and stiff
  • Wide leaf blades in a fan shape
  • Dense clumps of growth scattered in your lawn
  • Triangular or V-shaped stem
  • Solid stem with no nodes
  • Flowers in clusters at the end of a stem
  • Thistle-like seed heads in a spikelet formation

Yellow Nutsedge VS. Purple Nutsedge

nutsedge seed head

Though there are thousands of sedges and hundreds of different nutsedge plants, yellow nutsedge (Cyperus esculentus) and purple nutsedge (Cyperus rotundus) are the two species that you are most likely to see in Nebraska lawns. Both of these plants are perennial weeds, which means they will continue to be a problem for several seasons if you do not try to control them. As their names suggest, the most obvious difference between the two is the color of each weed's seed head, but other subtle differences can help you differentiate these two common weeds. Yellow nutsedge tends to be found more in moisture-rich soils of Nebraska, but a purple nutsedge invasion is also possible and is just as detrimental to your yard!

Yellow Nutsedge:

  • Faint yellow/golden-brown seed head
  • Taller stems (up to 3 feet)
  • Light green leaf blades
  • Pointed tips of leaves
  • Leaves longer than stems
  • Spreads via tubers and seeds

Purple Nutsedge:

  • Ruby/purple-brown seed head
  • Shorter stems (up to 2 feet)
  • Dark green leaf blades
  • Rounded tips of leaves
  • Leaves shorter than stems
  • Spreads via tubers (rarely seeds)

What Causes Yellow Nutsedge?

water puddling up on a lawn

The number one cause of yellow nutsedge, or any type of nutsedge, is excess moisture in the soil. Nutsedge weeds have very high moisture requirements, and they get increasingly aggressive with more water that becomes available in a particular area. This often means that yellow nutsedge will grow near rivers and ponds, but there are many situations that can breed a yellow nutsedge invasion right in your backyard. Lawns that have drainage issues lead to standing water, puddles, and excess moisture retention in the soil. If you have a damp or soggy lawn that has very little shade cover, beware of the following:

  • Compacted Soil: Lawns that are compacted are notorious for not being able to drain properly, which is an invitation for nutsedge to invade.
  • Overwatering: Too much rainfall or scheduled waterings can lead to your lawn retaining the excess moisture that nutsedge loves.
  • Bare Patches: Areas of your lawn that are bare or under-seeded can cause many drainage and compaction issues.
  • Mowing Low: If your mower deck is set too low, you can easily cause the aforementioned bare patches to appear.
  • Leaky Sprinklers: Automated irrigation systems often drip around the sprinkler heads, making them a common site for nutsedge.
  • Existing Weeds: Lawns that are already struggling with weeds will have existing drainage issues and less turfgrass, meaning more nutsedge!

The Spread Of Yellow Nutsedge

identifying nutsedge

If your yard falls victim to yellow nutsedge, an invasion will spread rapidly. The roots of nutsedge are notoriously difficult to control or remove, and they are the primary means by which an invasion is spread. Yellow nutsedge roots are known to go as deep as 4 feet into the soil, and they come in the form of complex tubers and rhizomes that spread out and invade the roots of your lawn or garden. These underground tubers and rhizomes sprout new shoots all over your lawn, even up to 10 feet away from the point of origin. Remember, yellow nutsedge weeds even spread seeds in addition to sprouting new shoots, so you always have to be mindful of conditions that could invite nutsedge even if you don't see any nutsedge in your yard.

Preventing Yellow Nutsedge

nutsedge overhead

Yellow nutsedge is one of the most invasive and aggressive weedy plants that you will find in your lawn. Due to its ability to spread its roots more quickly and deeply than many turfgrasses, we highly encourage any homeowner in the Lincoln, Nebraska area to call Summit Lawns for professional weed control services. Professional technicians like ours are your best line of defense against yellow nutsedge, as they can assist you in managing moisture levels and turf quality throughout the year. Our team will even apply a pre-emergent weed killer in early spring to block any yellow nutsedge from popping up in summer. We hope this post has been helpful, and be sure to keep the following tips in mind for preventing and treating yellow nutsedge:

  • Avoid pulling-up roots. This activates the tubers and will sprout new shoots, especially if the weed has flowered.
  • Use herbicide on mature nutsedge. Look for halosulfuron- or sulfentrazone-based products.
  • Improve drainage. Aerating or installing a drainage system will decrease the amount of moisture in the soil.
  • Monitor sprinkler heads. Automatic irrigation systems can welcome nutsedge if they malfunction or have leaks.
  • Avoid mowing low. Mowing your lawn too low can cause bare batches to form, which will invite nutsedge.
  • Increase lawn density. Fertilize, seed, and make sure your lawn stays lush and robust to defend itself against the dreaded nutsedge!