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Nutsedge or Nut Grass is a perennial weed that commonly invades lawns. In this article I will tell you how to identify and control nutsedge. It is an invasive species from Eurasia, and notoriously difficult to get rid of once it has been established in your lawn. There are two different types of Nutsedge that are commonly found in yards across North America, yellow Nutsedge and Purple Nutsedge. The primary difference is the color of the flower, and bloom time.

Nutgrass growing taller than lawn — The nutsedge is much taller than our lawn.

Common broadleaf weed killers don’t work on Nutsedge. This is not a typical broadleaf weed like dandelion or thistle, but a sedge. Just like with onion grass or wild garlic, Nutsedge will shed the herbicide, which is frustrating. (See how to control Onion grass and Wild Garlic HERE)

Facts about Nutsedge

It grows faster than most turf grass, creating an uneven lawn
Can’t be killed by common broadleaf weed killers applied to lawns
Native to Eurasia, North Africa and found throughout the world
It is not a ‘normal’ broadleaf weed, but a member of the sedge family
Yellow Nutsedge (Cyperus esculentus) primarily grows in mid-summer, and its flower has a yellow color
Purple Nutsedge (Cyperus rotundus) grows in late summer/early Fall, and its flower has a purple color
Yellow Nutsedge is grown as a crop in some parts of the world, as the tubers are edible

General Physical Description, Identification

nut grass rhizome runner — This plant was getting ready to send up new shoots via Rhizome.

Leaves/Plant

Nutsedge has yellow/green leaves and a triangular shaped stalk. There are generally three leaves growing from the base of the plant that curve over and bend back toward the ground. The plant generally grows faster than turf grass, giving it a tall appearance.

Another thing you probably have noticed is that nutsedge grows much faster than turf grass. It makes your lawn very unsightly and uneven.

Flower

A strange, spike-like flower will form at the top of the plant if not mowed. These flowers will produce seeds.

Roots

The roots of nutsedge plants consist of fiberous roots, rhizomes, and tubers. So, the roots are somewhat thick compared to grass, being up to 1/16″ thick (1.5 mm). At the end of some of these roots are small bulbs, also called tubers that sprout more plants. And finally, the rhizomes are long sweeping roots that will sprout more nutsedge plants.

nutsedge bulb nutgrass — Tuber or nutlet at the end of a root

Growing Conditions

Nutsedge needs warm soil and moisture. If you have clay soil, or poor draining soil that stays moist, then you are creating the right conditions for this sedge to thrive. Once colder temperatures arrive, the plant will go dormant and seemingly vanish from your lawn. Only to return early the following summer, once the soil temperatures get warm enough.

How Nutsedge Spreads

Nut grass has three different ways of spreading. By underground runners/rhizomes, tubers or nutlets, and seed.

Rhizomes – A rhizome root is a shallow root that extends horizontally through the soil. After it has grown a sufficient distance from the mother plant, it will send up a new shoot into your lawn. This plant will then develop into its own regular root system, and eventually begin sending out rhizome runners of its own. So, your infestation will get compounded.
Tubers – At the end of other roots, a small bulb will form. This bulb is called a tuber or nutlet. The plant stores energy here, and can resprout more Nutsedge from it. So, if you are wondering why more nutsedge seeming grows from nowhere after you have pulled out a few plants, this is the reason. The root will often break at the tuber, leaving it in the ground. The stored energy in the tuber will then send up a new shoot, creating a new plant for you to deal with.
Detailed view of a nutlet or tuber
Seed. Nutsedge will form seed if it is allowed to grow tall enough. They are strange looking seed heads, almost like little spiked balls. But these are seeds none the less, and they can germinate creating new Nutsedge plants.

How to Control Nutsedge

Prevention

The best way to control Nutsedge is to have a thick healthy lawn. Besides contact with the ground and moisture, most weed seeds also need sunlight to germinate. Having a thick, full lawn will often rob the weed seeds of sunlight. Additionally, having a thick lawn can sometimes ‘shade out’ small weed seedlings. You normally wouldn’t know or notice this, as you can’t see the weeds that died early. You just see the weeds that survive and plague your lawn. This is a form of survivorship bias, if you will.

Pulling up Nut Grass

Nutsedge rhizome runner — This plant was getting read to send up new shoots via rhizome roots.

For small infestations or isolated specimens of Nut Grass, pulling can be very effective. But you must be vigilant, and will most likely have to pull more nut grass from the area a week or two later. Possibly more if depending on how many plants you pull out.

To give you an example from my yard, last year we created a new flower bed on what was once a wild area, and the following Spring I had 200-300 sprouts once the soil temperature warmed up. I spent 20-30 minutes pulling them, and true to form I had to return a week later to repeat and pull up more. Only the second time there were about half as many Nut Grass plants. I had to repeat this process 3-4 more times, always with fewer sedge grasses sprouting than what I had pulled the previous time. In fact, the last 2-3 times I had to pull Sedge, there were probably fewer than 10. So, this is a very effective method of controlling a nut grass infestation, but it takes a bit of tenacity and perseverance on your part.

Mowing

If you are reading this, then you probably know full well that mowing nutsedge….. just makes more nutsedge. Not effective.

Chemical

Chemical control is about the only reasonable option for large infestations. There are numerous herbicides on the market for control. You just need to make sure that you use a product that is specifically labeled for Nutsedge. Normal herbicides that only kill weeds (not your lawn) won’t harm Nutsedge. Products that specifically kill nutsedge generally tell you in the name, such as ‘Sedgehammer’, or ‘Nutsedge Killer’ and are available from most big box stores.

Read the label, put on some personal protection equipment, and follow the instructions. You may need to do more than one application since the small tuber/nutlets at the end of the roots can still sprout more plants.