Depending on your point of view, you will either consider monkey grass a lovely ground cover or an unwanted weed. If the latter is more of your mindset, these tips for controlling monkey grass will help you get rid of your unwelcome garden visitor.
Check Craig’s list free advertisements on most weekends in the summer here in NC and you will see ads for free monkey grass plants touting the words “all you have to do it dig it up yourself.”
There is a reason for these ads. It is the way clever gardeners keep their liriope plants under control without having to do it themselves!
What is Monkey Grass?
Liriope, commonly known as “monkey grass” or “creeping lilyturf” is a grass like plant from Asia which is often used as a ground cover or border plant.
Oddly enough, in spite of the common names, it is neither a grass or a lily. It is a member of the family Asparagaceae. Given the right conditions, monkey grass will grow aggressively and can take over a border in no time at all.
I have monkey grass in several areas of my garden, but I have to keep an eye on it, or it will spread everywhere. The perennial plant spreads by means of runners which are easy to transplant to other areas of the garden.
Did you start out with a nice border of liriope and found that it has started to invade your lawn or garden beds? Do you often find yourself asking “how can I get rid of this darned stuff?
Never fear, you are not alone. Many gardeners feel the same way.
Unfortunately, if left untended, monkey grass can be quite difficult to remove since if forms dense clumps that seem to go on forever. The following tips will help you get rid of or control monkey grass in your yard.
Controlling Monkey Grass
There is no “one way fits all” method of getting rid of monkey grass. A lot depends on how early you get to the job and how entrenched it is in your yard or lawn.
Start Early and Stay on Top of the Job.
If you are only trying to keep the liriope under control but want to allow some to stay in the yard, you’ll need to be vigilant. The plant sends out runners all during the growing season. When you see them starting to grow out into the lawn or garden bed, remove the runners.
It is much easier to keep it tidy than to have to dig up a whole garden bed that’s been taken over.
Digging
If you let monkey grass grow un-managed, you will have a job getting rid of it!
I know you were looking for an easy answer but the best remedy involves some real work – digging. If you have tried just pulling up the runners, you will know that they break off easily.
Digging the monkey grass will get the roots and will keep the spreading nature under control.
Use a spade or shovel to dig down around the liriope. Till the area around the removed plants and over the ground with plastic or newspaper to help choke out further growth.
This takes patience, since you may need to repeat this process for several months if you want to get it all.
Barriers
Since the plant spreads by means of underground runners, adding barriers is a good practice for controlling monkey grass. The barriers must go down into the soil quite a way – 12-18″ is a good size.
If you use barriers that are too shallow, the plant will simple go under them and come back up on the other side.
The barriers do not need to be plastic. Other ideas are trenches, landscaping fabric, plastic sheeting, or mulch.in channels dug near the plant
Containing it
Controlling monkey grass when you want to use it as a border is easy if you think ahead when you plant it. Did you know that you can control it in your garden and still have the lovely border that you want by simply planting it in containers in the first place? \
Instead of planting the liriope directly into the soil, sink the plant pots side by side and mulch over them.
The look will be the same, but the plant won’t be able to send out underground runners and you won’t have it invading nearby garden spaces. You’ll have a lovely border without the hassle of having to keep removing spreading monkey grass babies!
Note on this method. The plants will eventually become pot bound and will need to be removed and divided. You an either use the extra plants in other areas of the garden, give them away or add them to the compost pile. 
Know your types of Liriope!
Some types of liriope are fairly easy to keep under control. I have Liriope muscari and a variegated liriope called Liriope muscari ‘Variegata’.
Both of these are a gentle clumping type of monkey grass. They can be controlled easily by digging and manually removing the unwanted plants and roots.
If you love the plant and want to grow it, the variegated variety is much slower growing and far less invasive. I have had some for 4 or 5 years and it comes back every year but barely spreads.
Other types of liriope, particularly liriope spicata, are much more aggressive, making digging and tilling very difficult. If you have this variety planted you will be in for a shock when you start to dig it out.
When you consider the effort that goes into controlling monkey grass, you can see why it’s either loved or hated by gardeners. Which category do you fall into?
42 responses to “Controlling Monkey Grass – How to Get Rid of Liriope”
a “neighbor” with an unkempt yard planted (threw) some that rooted and is now invading our lovely (kept) lawn. what can we do to stop it from ruining our landscaped lawn?
Hi Diae. The very best way to control liriope is to dig it out. The plant spreads from underground runners and even with digging you are likely to get some that still root. Carol
We have the same problem. I’ve been fighting it for five years. I’m losing the battle and am just about ready to move.
We bought a house that has it everywhere. And the worse part…it was planted in a bed of 2-3″ rocks!! I don’t know what to do. Leave it and fill in the spaces it hasn’t invaded yet so it looks like it was supposed to be there or just remove all of it.
Hi Amanda. If you leave any of it, it will spread to fill the entire bed. Liriope grows from underground runners. It’s often used as a ground cover for that reason, but it is not always desirable.
My lirope growing along walkway to driveway is constantly being invaded with grasses that are ugly and a real pain to dig out. I am ready to kill off the lirope and replace it with a prettier sedum. How do I kill the lirope. I have to admit I sprayed it with Roundup, which killed most of grasses but not the lirope!
Round up won’t do anything to liriope. The plant is tough and sends out underground runners. The only real solution is digging it up and even then, you’ll get some of it come back the next year and will need to dig again.
I have my work cut out for me on this plant. I had noticed some of my lilley’s in the flower garden were ,at one time at the edge of the garden, now quit a ways back in the garden. I went to inspect the situation and found that the monkey grass had grown 2 feet out. I then wondered what this plant was capable of. I was shocked when I read your page. It is going to take weeks to get the monkey grass cleared out as it is planted more then 200ft down the flower bed plus 2 other areas that are 20ft. I plan to dig it up and replace it with the variegated variety. I think your idea of planting it in container’s and sinking them side by side will be a better way for me to keep an eye on it. so I have a lot of work to do to get to a happier garden and a happier me. thank you.
I had pretty much the same situation and had to dig mine up too. I now use the variegated version without a problem. The plain stuff is tough!
hi! I am one that uses monkey grass alot….my problem is the “other grass” that grows up into the monkey grass…I was told by an elderly woman that the only way to keep monkey grass “clean” was to pull the “other ” grass by hand, hasn’t mankind made a spray that will kill the “other” grass and not kill the monkey grass?
Hi Tina. I rarely use sprays in my garden, so I am afraid I don’t know of one.
Yes, you need to oil mix with hi-yield grass killer
@tina boggan, I bought a house where the previous owner planted monkey grass in a huge bed in the front yard 40 years ago. It has spread under and through the brick walk way across the next flower bed and into the front driveway. Someone at a garden center that I purchase grass killer to kill it in the walkway. Didn’t touch the monkey grass at all. (I think it made it mad) My solution so far is to mow it into a lawn and slowly “shape” the garden beds to limit where it goes. It does make a lovely and slow growing lawn.
How do you smother monkey grass to death? I pulled the leaves off and put six layers of newspaper on the ground and then covered it with a layer of plastic. On top of that am placing ground cover to prevent grass from growing. On top of that am placing a couple of inches of mulch. Please tell me that will work.
How do you smother monkey grass to death? I pulled the leaves off and put six layers of newspaper on the ground and then covered it with a layer of plastc. On top of that am placing a couple of inches of mulch. Please tell me that will work.
Monkey grass is one of the toughest plants that I have come across. The only way that I have found effective in really controlling it is to dig it up. Even then the roots may produce more that will need digging up.
@Margret Sheffield, It grew up through the weed barrier I had down all over my flower bed
Posts will control Bermuda grass in regular and variegated monkey grass. Image will control nut grass in it.
Can I keep monkey grass short? Mine is too tall for my liking. This would require trimming/cutting a few times per year. North Texas.
Hi Todd. if you cut it, the grass will bush out and still grow up, so it would require frequent trimming.
Your article has conflicting information in it. You say that monkey grass (Liriope) is not a grass, which is true, but then recommend grass killers such as Poast and Fusilade as chemicals that will control it, which is false. Chemicals in these products, sethoxydim and fluazifop-p-butyl respectively, are specific to grasses so they won’t harm monkey grass which isn’t a true grass. I would suggest removing that section of your article. Also, it is true Liriope has some tolerance to Roundup, or products containing glyphosate, but it can provide some control if applied properly at the right rate and with persistence; one application won’t get rid of it.
Thank you for the information David. I’ve removed the recommendations for the grass killers based on your info. I appreciate you taking the time to suggest it. I didn’t add the part about Round up since so many gardeners are against using it, but will leave this info in your comment. Carol
If I spray the shoots with round up, will it kill the whole plant or just the runners? I would like to keep the plant themselves.
It will likely damage the plant (and could kill it) but not the runners. The only way to stay in control of the runner, in my experience is to remove them as they grow. Liriope is very invasive.
What if I put large stones along the border of my monkey grass? Will that reduce spreading? I like the monkey grass, I just like it in a neat row!
Monkey grass will even grow underneath asphalt walkways. Large stones may keep them contained for a while but eventually they will find their way under them.
I have a HUGH long bed that is surrounded by loriope….it is a nightmare…which variegated loriope do you have that is just in a clump???
It is called liriope muscari variegata. I’ve written a post about it here.
@Carol Speake, thanks soooo much…!!!
Will boiling water slow it down?
Temporarily but it will also kill plants nearby.
Will Roundup kill monkey grass? I love monkey grass but it is getting in the way of my air conditioner drain outside so some of it needs removing. I am not able to dig it out due to my age.
Monkey grass grows from underground runners and is very hard to kill without digging the entire plant and roots up.
I really need some help, I have a lot of nice monkey grass I planted many years ago but wild African violets have invaded it. Now it looks awful with the violets mixed in. How can I kill the violets and not hurt the monkey grass? I know it will have to be a chemical spray of some kind but I don’t want to kill my monkey grass.
I don’t use chemicals much but the only thing I can think of is to “paint” the roundup directly on the wild violets. However, they grow from underground roots, so killing them will be very difficult.
I’ve been saving my paper coffee filters and use one at bottom of pot for drainage. It keeps the potting soil from leaking out but allows water to drain. I’m betting that if I line the hole for a monkey grass plant, it should slow down the spreading of new plants. Is that a logical assumption? My HOA neighborhood uses recycled water so I’m having to supplement the alkaline soil with acidifier and used coffee grounds. to correct the PH.
I”ve never tried this but I assume it would have some effect. Eventually, though the coffee filter would break down and the grass would still grow outside the hole.
I had to dig it all up. It was taking over my flowerbed. Thanks for the information. I also had weed barrier down and this stupid plant grew up through the barrier. Very strong willed plant.
I planted the invasive lirope by accident in my mulch bed, I have tried all summer long to try and kill it. I have put everything on it. Round up, poison ivy killer, diesel fuel, boiling water, vi e & brush killer, and nothing works. I have dug it all up, and sprayed the ground, covered it with a tarp. But it still comes back. I’m going to try again this fall and see of I can kill it over the winter when it’s ot growing so aggressively. If anyone has successfully killed lirope, please advise. Much thanks.
I managed to get mine all up with digging and then consistent pulling out of any stray pieces over about 2 years. It was in a row along border though, not filling a while bed. In the bed where it had bigger clumps, my husband dug it up. Digging really is the only way that works for me, and then redigging when some comes back. Covering the entire area with black plastic might kill it all, but it will kill everything else too.
@Carol Speake,
I have had it with the variegated liriope. It was planted in 5 beautiful clumps about 13 years ago. At that time, Thick fiber weed barrier was laid down then several inches of river rock, and then the plants were dug in. Now it is a major task just to get under all that to get to the roots. I think that the layers on top of the soil encourages the runners underneath. So I am removing everything. Then will work the soil to pull out as much as possible. The weed barrier is going in the garbage but I will return the rock to the bed. I will never plant monkey grass again.
I have pretty good luck with variegated liriope here in NC but the all green variety is a no no with me now.