How to get rid of Sedge Grass

There are hundreds of sedges in the genus Cyperus, which is found in both tropical and warm temperate environments across the world.

Some Sedge Grass is grown as ornamentals or pot plants, while other species with edible tubers are used for food and as a spice.

Australian types include Umbrella Sedge, Flat Sedge, Nut Grass and Mullumbimby Couch and despite their common names, Sedges are not grasses.

Sedge Grass can be annual or perennial and grows in shallow still or slow-moving water, as well as poorly drained areas and wet spots in your lawn.

They can spread by seed or rhizomes and are often brought into gardens by water, animals, mowers, or in contaminated soil.

What to Look For

Some Sedges might look like grass in your lawn when the plants are small, but they are distinguishable by their stiff, narrow leaf blades, triangular stems and prolific seed heads.

Sedge Grass can reproduce by seed, from rhizomes, or both.

The best way to identify which species is in your lawn is from the seed head, but the best time to remove Sedge Grass is when plants are small and haven’t had time to produce seed.

Umbrella Sedge Weed

Umbrella Sedge (Cyperus alternifolius) is also known as Umbrella Palm and Umbrella Papyrus a long-lived reed-like plant with upright stems which usually grows 45-120cm tall.

Often used in ponds and water features, Umbrella Sedge has escaped and become a common weed of waterways and wetlands across Australia.

Umbrella Sedge reproduces mainly by seed but can spread from its short rhizomes to form large clumps.

Flat Sedge Weed

Flat Sedge (Cyperus eragrostis) is also known as Tall Nut Grass, Tall Flat Sedge and Umbrella Grass.

It grows from rhizomes and has erect stems up to 90cm tall, with long, thin, pointed leaves radiating from the top.

Flat Sedge is regarded as an environmental weed in New South Wales, Victoria and Western Australia.

Nut Grass

Nut Grass (Cyperus rotundus) has a very narrow leaf and is easily distinguishable from most turf varieties.

It’s an annoying fast-spreading long-lived perennial weed that grows from underground tubers.

There’s more information about how to take control of Nut Grass here.

Mullumbimby Couch

Mullumbimby Couch (Cyperus brevifolius) is also known as Short-leaf Flat Sedge and Perennial Greenhead Sedge.

It is regarded as an environmental weed in parts of Western Australia, Queensland, New South Wales and Victoria.

Plants produce reddish-purple rhizomes which send up smooth, hairless three-sided stems and flower spikes that produce pale green seed heads all year round.

Mullumbimby Couch reproduces from both seed and the creeping underground runners.

There’s more information about how to take control of Mullumbimby Couch here.

How to Get Rid of Sedge Grass in Your Lawn

Sedge Grass can be difficult to eradicate because it produces a large number of seeds and has an extensive system of underground rhizomes and tubers.

The main options for controlling Sedge Grass are mechanical and chemical methods and they are more likely to succeed if undertaken when plants are actively growing, not stressed and haven’t seeded.

Mechanical control of Sedge Grass

Small individual Sedge Grass plants with less than five leaves won’t have grown tubers and can easily be removed by hand.

Larger Sedge Grasses can be dug up with a sharp spade, taking care to leave a generous margin around and under the roots, as well as making sure you pick up all of the runners and any bulbs that might be left behind.

Slashing and mowing can be helpful in bigger areas, but make sure the Sedge Grass is dry. If it’s wet, the seeds can stick to you and your equipment which can lead to further spread.

Avoid cultivating Sedge Grass – chopping it up will also spread it.

Chemical control of Sedge Grass

Applied correctly, glyphosate can be effective on Sedge Grass, but as a non-selective herbicide it will poison everything it touches, including the surrounding lawn.

Products containing the active ingredient halosulfuron-methyl can be safely sprayed on many turf varieties to kill Sedge Grass, while others should only be used for spot application. This includes products containing MCPA that are marked on the label as being suitable for Paspalum, Nut Grass and Clover.

Depending on the maturity of the Sedge Grass plants and how large an area is affected, it may be necessary for you to spray more than once.

Always read the safety directions and instructions on the product label before use.

Recommended Products

Indigo Halo Force Herbicide 25gm

Indigo Halo-Force 750WG 25gm is a dry flowable granule herbicide. Grasses that Indigo Halo-Force 750WG can be applied to are KikuyuCouch and Buffalo. Always read the safety directions and instructions on the product label before use.


Tuffweed Liquid Glyphosate 1L

TUFFWEED Liquid Glyphosate 1L super concentrate is a non-selective herbicide. Before use always check to see if your lawn variety is suitable for the use of TUFFWEED Liquid Glyphosate 1L. Always read the safety directions and instructions on the product label before use.


How to Prevent Sedge Grass in Your Lawn

A program of regular fertiliser application and mowing that ensures you have a strong, healthy lawn provides the best defence against infestation by weeds such as Sedge Grass.

Learn what kind of lawn you have and take care of it properly using the right kind of fertiliser, maintaining the optimum soil pH and mowing your lawn to the recommended height.

Other preventative measures of Sedge Grass include fixing any drainage or irrigation issues and stopping water from collecting in hollows in your lawn.

Top-dressing can get rid of small dips, but in larger poorly drained areas, it might be necessary to remove a section of lawn. You can put down a mixture of compost, sand, or other amendments to increase the porosity of the upper layers of soil and then re-lay your lawn on top.

Another way to stop Sedge Grass in its tracks is by laying geofabric under new garden beds to minimise the risk of it spreading from seeds or tubers in soil that’s brought in.

Free Lawn Guide

Sign up for our Newsletter to receive your free guide.

View our Privacy policy

Related Articles

How to Remove Catsear Weed (hypochaeris radicata) from Your Lawn

Often mistaken for the English dandelion, catsear weeds can quickly ruin the aesthetic of your lush green garden oasis, with the appearance of yellow flowers in the middle of ...

Read More

How to Remove Cudweed from Your Lawn

A true broadleaf weed, cudweed is prevalent in winter lawns, when it grows vigorously and out-competes many grasses. Starting with one plant, it forms unsightly clumps that ...

Read More

How to Remove Dollarweed (Pennywort) from Your Lawn

Dollarweed, also known as pennywort, is a nuisance: this water-loving weed can spread quickly and can be difficult to eradicate once it becomes established in your lawn. ...

Read More

How to Remove Thistle Weeds from Your Lawn

Although recognised as the national flower of Scotland, thistles are in fact considered weeds in most parts of Australia. Like most broadleaf weeds, they present a problem for ...

Read More

Removing Plantain Weed (Lambs Tongue) from Your Lawn

Found across Australia, plantain weeds are ugly intruders commonly found in lawns that are neglected or in poor health. Characterised by a flat rosette of leaves and a tall ...

Read More

Broadleaf Weed Identification Guide Australia

Broadleaf weeds can quickly ruin your beautiful lawn, creating an ugly eyesore in your green oasis. Unlike grass weeds, they tend to be easier to spot, which makes identifying ...

Read More

What are Grass Weeds? – Your Guide

Weeds are a common problem in most Australian gardens, impacting the look, and sometimes the feel of your lawn. Grass weeds are especially good at surviving, as they are often ...

Read More

How to Remove Burr Weeds from Your Lawn

If you've ever stepped on a round spiny ball while walking barefoot on your lawn, there's a good chance your lawn has burr weed. Also known as burr medic, this sprawling weed ...

Read More

How to Remove Carrot Weed from Your Lawn

This daisy-like weed is quite sweet and unassuming, but like its cousin the lawn daisy, carrot weed can become a problem if left unmanaged in your lawn. Native to Australia, ...

Read More

How Can I Get Rid of Daisies in my Lawn?

Daisies can be a beautiful addition to a garden, but they can also be a nuisance when they make their way into the lawn. Known for spreading quickly, these wildflowers can ...

Read More