Do you have Liriope muscari or Ophiopogon japonicus? Chances are you have one or the other if you live in the South. Before you panic thinking you may have contracted a disease from mosquitoes or an awful foot fungus, relax. These horrible-sounding names are two of the most common ground covers in landscaping.

Both have been used for years to edge driveways, sidewalks, and flowerbeds. Because they spread and are almost impossible to kill, they are often given away as pass-along plants. Many people refer to both plants as monkey grass.

Related Features:
Caring for Your Ground Cover
Divide and Conquer
Liriope
Mondo Grass

Caring for Your Ground Cover

Mondo grass and liriope can both suffer from cold damage during bad winters; foliage can turn brown and look rough. You can run a lawnmower set on its highest setting or a string trimmer over them in late February to remove discolored foliage before new growth appears. When trimming, don't cut too close to the crowns of the plants or you may hurt new foliage. Even when cold damage isn't a problem, it helps to cut these plants back every few years to rejuvenate tattered foliage and promote new growth.

These ground covers are good for more than just edging. They make a nice sweep of green in the landscape and can be used as a low-maintenance lawn substitute. They excel under trees where many turf grasses struggle. Planted on steep banks, they help hold the soil and prevent erosion. Drought tolerant and rarely bothered by pests, they also look good in pots, either planted alone or in a mix.

Divide and Conquer

If you already have one of these ground covers and would like to divide it, don't worry. Liriope and mondo grass can easily be lifted, separated, and planted in other locations. Or you can buy them in flats or small pots. Buying lots of small pots may seem like an expensive way to go, but remember--if you have to buy your plants, you can divide them and get several sprigs from one pot. Use a sharp hatchet or knife to separate tight, root-bound clumps, and then cut off the bottom half of the roots with clippers. This will not harm the divisions, but will promote new root growth.

Space liriope 8 to 10 inches apart and mondo grass 4 to 6 inches apart. Large plantings should be put out in a gridlike pattern. If the soil is loose and you water and fertilize periodically, they should mesh tightly together in a couple of years.

Mulch new plantings with finely shredded bark. Bark keeps weeds out and moisture in. It also allows stolons to move under the mulch so plants can spread.

Liriope

Liriope muscari ranges from 12 to 24 inches in height. When not called monkey grass, it's also known as lily turf or simply liriope. 'Big Blue' is the most popular and available selection. The leaves are 1/2 to 3/4 inches wide. Liriope is usually dark green in color, but some selections, such as 'Silvery Sunproof' and 'John Burch,' have striped white or yellow leaves. Those selections tend to do better in sunny locations.

'Evergreen Giant' grows tall, usually 2 to 3 feet in height. It makes a nice foundation planting against the house under low windows. It isn't as cold tolerant as other selections and is best suited for the Coastal and Tropical South.

Liriope spicata, sometimes called creeping liriope, has soft narrow foliage. Because its foliage is not stiff, it forms a loose mound. It isn't recommended as an edging plant because it spreads aggressively and will quickly grow into turf areas and flowerbeds. It works well in large beds as a ground cover, where weeds have a hard time competing with it.

Liriope thrives in a moist, fertile, well-drained soil and will take sun or shade. Roots, known as stolons, move underground, allowing the plants to spread. More popular for its foliage, liriope does have attractive summer flowers. 'Majestic' has the showiest, producing spikes of purple that fan out at the top of plants. Liriope blooms are usually violet in color, but 'Monroe's White' has cream-colored flowers.

Mondo Grass

Ophiopogon japonicus, commonly referred to as mondo grass or mondo, is very similar to liriope but much smaller, growing 6 to 12 inches tall with 1/4-inch-wide leaves. Its fine texture makes it a good ground cover in tight spots

Mondo grass is not recommended for full sun locations because of leaf burn. A little shade allows it to retain a deep blue-green color. 'Silver Mist' is a variegated form with green-and-white leaf blades. There is also black mondo grass (O. japonicus 'Nigrescens') which has very dark foliage. This selection is more of a specimen plant and is slow to establish itself. Dwarf mondo (there are several dwarf selections) is tiny, growing only 3 inches tall. Many times dwarf mondo is used in cracks and crevices of walkways. Its low profile keeps it from interfering with your footing.