Monkey Grass

May 5, 2018

I have 2 types of monkey grasses in my front beds--the striped and the solid green.  In one bed the solid spread and now occupies all of one end.  Last year I dug up roots and all but it came back even thicker.  Can it be killed totally without using a poison of any kind?  Would vinegar help?  I just want it gone--all of it.

There are two types of liriope or monkey grass-not just variegated and green.  There are clumping forms and spreading forms, and they both have variegated and solid green plants available.  The spreading form is Liriope spicata and is quite invasive.  You can dig up as much as you can and then watch what sprouts from remaining roots and spray those with a glyphosate product (Round-up). It will take a few seasons before you are monkey grass free.

 (June 2010)

I have a fifty foot border of monkey grass along my front walkway. I am threatening to dig it up and replace it with a rock border because I can't keep the Bermuda grass out of it. Other than hand pulling it out, which would be a daily chore, do you have any suggestion to getting it and keeping it under control? We love the look of the monkey grass but the Bermuda makes it very ugly. I would appreciate any suggestion you may have.

I have two suggestions. One is to invest in a grass specific herbicide that can be sprayed on the monkey grass or liriope (Liriope is in the lily family, and is not a true grass). Poast, Fusilade, Grass-b-gone, Ornamec and/or Over-the-top are all brand names. Try to get these products sprayed as soon as possible, since the grass is getting a strong foot hold and dead grass can be just as unattractive as live grass in the liriope. Once you have the grass under control, create a buffer zone between your lawn and your monkey grass. It should be at least six to twelve inches wide. You can use some type of edging or mulch here, but it gives you some space to keep the lawn in check either with a weed-eater, edger or chemical. Whenever we have our beds directly adjacent to running grasses, the grass takes over.

(July 2006)

I need a good sidewalk border that will look good all year round with some.

Do you really need plants running the length of the sidewalk, or can the lawn be enough? If you think you need some type of planting, make sure there is a distinct border between lawn and plants. Many times you see monkey grass or daylilies flanking a sidewalk and they are a mess of grass and plants. A buffer zone that can be edged or weed-eated can help. You didn't mention if you had sun or shade. If you have sun, perennial verbena can be a nice addition, but usually won't live more than 3-4 years. Stella d'or daylilies can bloom for a long period of time and are only dormant for a month or two in the winter and candytuft is an evergreen perennial with beautiful white spring flowers. Monkey grass (Liriope) is evergreen and takes sun or shade, but isn't particularly colorful unless you go with a variegated form. You could always do a mass planting of low growing shrubs, but they usually aren't necessary the entire length of the sidewalk. For shade plants, try ajuga with great colorful foliage, heuchera--many different colored varieties to choose from and they are evergreen, or pachysandra an evergreen groundcover.

(April 2010)

I have tried and failed numerous times over the years to get either Zoysia or St. Augustine sod to grow on the north side of my home (in the alley between our home and the house next door). My wife and I have decided to consider a ground cover of some type in lieu of grass. Could you possibly point us in the direction of some appropriate types of ground cover for this area which has little, if any, sunshine, year round?

Several choices come to mind, including moss as mentioned in earlier columns. If you want a grass look-alike there is Mondo grass (Ophiopogon) and Liriope or monkey grass--if there are strong borders limiting growth you can use Liriope spicata--the running form, but it can be invasive; the clumping form is Liriope muscarii. Other options include Ajuga, pachysandra, and Creeping Jenny- Lysimachia nummularia--I really like the golden form. Mazus, pratia and ardesia are other choices.

(November 2006)

When is the best time to trim azalea bushes and monkey grass?

Don't prune your azaleas any more now, wait until after they bloom. The flower buds are set for next spring’s display, so any pruning now will cut off flowers. Prune as needed immediately following bloom up until mid June. Then let them grow and prepare to set more flower buds for the next season. For monkey grass or Liriope prune in late February before the new growth begins. Cut off the spent foliage to clean things up for the new growing season.

(March 2005 )

We moved here 5 years ago and bought a home with a beautiful landscape. The former owner planted (on the advice of her landscape architect) a few clumps of that monster called "Monkey Grass". We have been told that it is a form of liriope or mondo grass. We have plantings of true liriope that simply stay in nice, self-limiting clumps, however, the other one, the monster, spreads wildly by subterranean runners and is unbelievably invasive. We ruthlessly dug up all we could see, but it just seemed to relish it. It is coming up inside all the major azaleas, ferns, hostas, etc. Can you suggest a herbicide that will kill this monster? We tried numerous chemicals, including Round-Up, but the monster responded as it if were fertilizer. We can't tolerate it. Should we just move? We hate to contemplate it, but our outdoor living area and our gardens are our life, and if there is no cure for the monster, we would rather just take the punishment and the financial loss and move on. In passing, we would like to suggest that any landscape architect (certified or novice), developer, or plant and/or garden center, no matter how small, recommending, or even offering, this horrible plant be automatically committed to some small, very cruel, Central or South American jail for a very extended stay with unspeakable punishment.

Occasionally everyone makes a mistake, and sometimes what seems like a great plant, takes over. Think about kudzu, Japanese honeysuckle and common privet. They were all planted intentionally at one time, and then took over! There are two basic types of monkey grass or liriope. The one most people want is Liriope muscari--the clumping form. Unfortunately, I think the one you have is Liriope spicata--the running form, and run it does. It spreads by underground rhizomes, and can be quite vigorous—(as you have learned), and unfortunately--hard to kill. Moving is by far the easiest method to fight it, but should you let a plant beat you? No, I didn't think so. Cut out as much of it as you can. If you can get a tiller in the beds, till it up, and then use a heavy lawn rake and rake out as much of the root system and crowns as possible. Then wait for new growth--which is inevitable. Then spray with a glyphosate (Round-up) product. I know you have tried it in the past, and didn't have good results, but use it on the young growth, wait two weeks and spray again. Repeat as needed. There is nothing else you can use around other plants without injuring them--use caution even with the Round-up--only spraying what you want to kill. If you are diligent this season, you should be able to conquer it--but don't turn your back on it, or it can reappear!

(November 2005)

My neighbor and I were wondering if we could cut back our variegated Liriope now instead of spring

I know that there has been some damage to Liriope or Monkey Grass this growing season due to the dry, hot summer. If it is really hideous, I guess you could cut it back, but in my opinion, the cut look is not that much better, and you may have to cut even further in the spring. Doing the pruning in the fall could lead to some winter damage--however, Liriope is a tough plant. We often get some discolored leaves during the winter, and use the late winter/early spring pruning as a means of rejuvenation and clean up.

(April 2005)

I have Monkey Grass that is 9 - 15 inches tall; it is very ragged looking and the tips are brown. I want to cut it back for new growth. How short can we cut it and it still thrive.

Cut away but do it quickly. You normally can cut it back to almost the soil line, but since it is so late, you don't want ragged, cut tips on the new foliage, so be a bit more sparing. See how tall the new growth is and selectively prune around it if possible. If you don't cut the old foliage off, the plants will look bedraggled all season.

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