Groundcover - Monkey Grass
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  (March) 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!

  (March) Is it time now to cut my monkey grass and my butterfly bush?

  Yes, now is the time to cut back all ornamental grasses and summer blooming plants such as buddleia, summer spiraea and roses. When cutting the grasses, be sure to check to see how much new growth is emerging, so you don't cut it too closely. On buddleia or butterfly bush, cut it back severely to encourage plenty of new growth and flowers.

  (April) I have Monkey Grass that is 9 to 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.

  (July) I divided and transplanted some Big Blue liriope about 5 years ago. The transplanted plants have done very well until this year. They are planted in a flowing line as an edge to a flower bed under the oaks in my backyard. Slowly but surely, each clump seems to be turning brown and dying from the middle outward. I'm at a loss on what could have caused this. The original liriope edges my patio and looks great. I applied fertilizer with weed killer earlier in the growing season (mid-May, I think), but have never had problems with the weed killer in this before. I'm gradually replacing some of the lost planting with new plants, but wonder whether I will see it die also. Do you have any suggestions on what might be causing this?

  Dig up one of the plants and investigate. Are the roots white and spreading out, or are they limited, brown and slimy? Root rot can lead to death. Do you see any insects such as grubs in the soil? If you can't find anything by looking, you may want to take a plant sample in to the local extension office. Liriope is usually tough as nails, so when it starts dying you need to take notice!

  I have a canna bed that is circled in monkey grass. The problem is Bermuda grass has invaded the bed and is making it pretty tough on the cannas. Is there anything that I can use to kill the Bermuda that won’t harm the cannas? Also, I have cut the multitude of monkey grass around the house and would like to keep the Bermuda from getting any worse in it. What can I do? (Altheimer)

  Try to get out as much of the Bermuda as you can now as it is greening up. Then, when the Bermuda has completely greened up, spray with a grass specific herbicide such as Grass-b-gone, Ornamec, Poast, Fusilade, etc. Depending on which product you buy, some have a crop oil mixed in with them, others you need to add this to the mix. Follow the label directions and try to use the product early, but after the grass has fully greened up. If you wait too late, it will kill the grass, but you will have a lot of dead grass to look at in your ornamental beds. Be sure you have a separation between lawn area and beds to help keep the grass out. Then regular edging can help.

  I need help! When I put in my yard a few years ago, I planted some liriope, not knowing it was so invasive. It’s spreading all throughout my flower bed. Is there anything I can do to contain this, or prevent its spreading?

  There are two main types of liriope--Liriope muscari and Liriope spicata. You obviously have the spicata type, which is a running form of the ground cover. The muscari form grows in clumps which can enlarge in time, but it is not considered invasive. The spicata type tries to take over and doesn’t form large clumps, it spreads by rhizomes and can quickly crowd out everything. It is great for areas that suffer from erosion where few other plants are growing. Try digging up as much as you can, then try spot spraying with a glyphosate product, such as Round-up. It won’t be easy to control this, but you can in time get a handle on it.

  I have grown the solid green Monkey grass for years, and last year I planted some variegated type. Right now they look awful, the variegated some worse than the solid green. Does it require annual pruning like the green forms, and if so, when do I cut it back and by how much? (Jacksonville)

  All ornamental grasses (including the lily family members such as monkey grass) need to be pruned yearly before new growth begins. Wait until late February to prune, leaving the dead foliage on the plants as extra protection for the winter. When you do prune, make sure that you check on the new growth to see how tall it has gotten. You don’t want your new foliage to have a cropped look.

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