control cogon grass

For some countries, cogon grass is native and a normal sight in grasslands and fields. However, in other countries, this is an invasive plant and something that people should get rid of. In this article we will talk about how to control cogon grass in your yard.

Cogon grass description

Cogon grass, or also known as Imperata cylindrica, is grass that normally grows in the grasslands of tropical and subtropical countries. Native to Asia, Australia, Africa, and southern Europe. Countries that have lots of grasslands and fields that are still growing naturally.

Cogon grass was introduced to Latin America, the Caribbean, and the southeastern United States. Cogon grass is a cause for wildfires all over the world. This is because cogon grass is highly flammable, even if the grass is still green. Some countries are calling this grass kunai grass instead of cogon grass.

Imperata cylindrica by road

How to Identify cogon grass

Long, thin grass that can grow anywhere from 2 to 10 feet tall. The leaves are about 0.8 inch wide at the base of the plant and are going thinner as the plant is growing higher. The upper part of the grass is hairy while the other parts of the plant are hair-free.

Seeds are small and attached to the top part of the grass. Cogon grass can be kept in control, by keeping it short, like other grass. However, in the long run, you want to make sure that you are getting rid of cogon grass for good.

Cogon grass close up

Cogon grass

Habitat of cogon grass

Cogon grass is native to places like Asia, Australia, Africa, and southern Europe. But, it can be found all over the world, in fields and grasslands that aren’t cut on a daily basis. The less cutting the grass gets, the more cogon grass will spread and grow. It mostly grows in moist sand.

In the native countries, cogon grass is growing all over the countryside. It is also grows in grasslands, and yards that are neglected. This grass is spreading really fast, and is growing just as fast as well.

Cogon grass US

Reports of cogon grass in the US

Is it poisonous?

Its high amount of silica makes it a big NO to consume. Its razor-sharp blades can cut when people or wildlife try to pass through its dense foliage. Young animals tend to eat it but usually stop feeding on this plant when they become adults. This is due to the sharp edges of the leaves that cause irritation in the mouth when they chew on it.

In many countries where the grass is growing native, people are using it to feed their farm animals. Especially during the dry season.

Medicinal value and other uses

There are some reports that cogon grass is used in traditional Chinese medicine. However, it is unclear if the grass is still being used today for making traditional Chinese medicine.

Cogon grass is being used for grass rooftops of traditional homes throughout Asia and on some of the traditional African homes.

The grass is also used to weave into mats and baskets.

Why is cogon grass invasive?

Even in the native countries, this plant becomes an invasive plant. This is because cogon grass is spreading really fast. It is growing rapidly and takes over grasslands and fields. In most countries, this grass is known as the worst weed in the world. It is hard to get rid of.

Cogon grass is also a danger because it is highly flammable and can catch fire, even if the grass is still green. This can have a negative effect on the environment and wildlife. Another reason why many countries find this grass a threat that needs to be taken out.

Today, cogon grass is among the Top 10 worst weeds in the world, specifically number 7. It is a threat to plants around it because it causes these plants to have limited growth and low survival.

Cogon grass is a noxious weed in rice, cotton, coffee, cinchona, tea, oil-palm, coconut, rubber and teak plantations.

How does cogon grass spread?

The wind can blow the seeds in many different directions. Where the seeds land, new grass will grow. Animals can also spread the seeds.

The major way it grows is through its underground rhizomes. Cogon grass can easily travel to new spots and start to reproduce from underground. These rhizomes reach about four feet into the soil. From the rhizomes, new plants are forming.

How to control cogon grass?

It is important to remove the plant as soon as you find it in your lawn or in your yard.

Cogon grass is spreading rapidly, especially in the raining season. It should be removed before it seeds. Once it produced seeds, it will be really hard to get rid of cogon grass. The sooner you are getting rid of the grass, the easier the overall removal will be.

It is essential that you remove cogon grass correctly. The roots go deep and regrow easily. Meaning that leaving a small rhizome behind, it will spread and start to regrow again. Leaving you with the weed all over again.

Early detection of cogon grass in any setting is extremely important. A young infestation will be much easier to treat and eradicate than established infestations.

Removing it during the dry season is the best. This is also the best time to get rid of all the roots as well. Chemical removal is recommended to ensure that there is no chance of the grass returning.

Manual control

Unfortunately manual removal of cogon grass seems impossible. There are people that are burning down the field, in order to get rid of the grass. But the grass will always grow back, because the roots don’t burn and die as what people might think.

Cultural control

Burn down the particular area where cogon grass is growing. Continuous flooding can also be helpful in eradicating this plant as it cannot stand continuous flooding.

Another method used is with the use of mulch. This can simply be added onto bare soil. This method of mulch application softens the soil and makes these cogon grasses easier to pull out. It maintains moisture in the soil which weakens this weed.

By planting a grass that can outcompete the cogon grass, for example lemon grass. One good thing about this grass is that after the job is done (outcompeting the cogon grass), you can easily kill off the lemon grass.

A natural method of removal will be the use of salt or vinegar. It should be applied continuously and overtime the cogon grass would not grow in that soil again.

A drawback to this method is the fact that the soil will remain infertile. That is, no other plant will be able to grow on that particular piece of land. This should be done more than once as with the chemical method.

Chemical control

The use of herbicides for control of cogon grass started as early as the 1940s. But of recent, only a few of those herbicides have proven to defeat cogon grass. Soil sterilizers such as prometon, tebuthiuron, and imazapyr will perform excellent in controlling the cogon grass.

However, areas treated using these chemicals will not be fertile for 6-12 months, which can prove non profitable for farm owners and may also bring erosion.

Glyphosate (Roundup, etc.) applied at 3-4 qt/A will substantially reduce the cogon grass but multiple applications are needed.

Roundup’s Glysophate will perfectly control all vegetation present at the time of treatment. After using this herbicide, crops can be planted immediately because glyphosate has low residual soil activity.

If large quantities of Roundup are used, slight soil residual may exist; therefore, wait for around ten to fourteen days before re-planting. Try to plant tender seedlings.

Fluazifop (Fusilade DX) provides moderate suppression of cogon grass. Fusilade is a selective grass herbicide that provides more dynamism when desirable broadleaf species are present for replanting.

Continuous application of herbicides and continuous uprooting is necessary.

Once control of cogon grass has been achieved, it is essential to introduce desirable vegetation as quickly as possible to prevent cogon grass from coming back to infested the area.

What you should keep in mind

  • Trying to mow down cogon grass with a lawn mower will only make the seeds and rhizome fragments spread to new areas.
  • Pulling out these plants will not do you much good because the rhizomes have grown deep.
  • Burning down cogon grass should take place during summer.
  • Protect yourself when using chemicals. Wear safety goggles, long sleeves, long trousers.
  • Herbicides is the major method to use when dealing with this plant.


Cogon grass can be dangerous because it is highly flammable, even if the grass is still green. It can take over a grassland easily, causing problems for the native grass and plants.

In the countries where the grass is introduced and where it isn’t native, it is a weed that needs to be removed as soon as possible. It is a known invasive plant because it grows rapidly and has more than one way of spreading. It is hard to get rid of.

The best and most effective way to remove cogon grass is to make use of chemicals. However, you need to make sure that you are using the right chemicals.

The sooner you are getting rid of it, the better.