Saturday, July 25, 2009

Liriope: A Favorite Ground Cover

Some plants are so familiar that you might think they are "from around here." Such is the case with Liriope (pronounced la-RYE-o-pee), commonly known as lily-turf or monkey grass. Many Americans like a sense of order, and Liriope provides it as it borders walks and driveways from street to door. But Liriope, like many of our favored ornamental plants, is native to east Asia.

The genus was named for Liriope, the "wave-blue water-nymph" and mother of Narcissus. Narcissus, you will recall, was the mythological character who adored himself way too much. The evergreen, grass-like plant is in the Lily family. Mature height is usually from 8" to 18". Flowers usually in shades of blue may be clustered around upright spikes, depending upon the species. Flowers are followed by small black berries with an opalescent sheen. Perhaps a scene of Liriope en masse inspired the name.

Liriope prefers moist soil in partial shade, but will also thrive in full sun tolerating drought and heat very well. The plants reproduce vegetatively by underground rhizomes of various lengths, young plants appearing at the ends. When rooted, the rhizomes can be severed (divided) and the young ones replanted elsewhere.

Liriope, depending upon the species, is used for ground cover and perennial borders. Taller cultivars such as L. muscari 'Evergreen Giant' and 'Densiflora' may be used for height and texture in container gardens.

Two species of Liriope are commonly available: Liriope muscari and Liriope spicata.

L. muscari is named thus because the blue flower spikes resemble those of Grape Hyacinths (Muscari armeniacum). In addition to "lily-turf" and "monkey grass", it is commonly called "border grass." Leaves grow up to 1/2" wide and up to 18" long. Foliage may be variegated. Flower colors range from blue to pink to white. It is reliably cold hardy in USDA climate zones 6 through 10. Recommended soil pH is 6.0 to 7.5. L. muscari grows on fibrous roots and tends to produce shorter rhizomes, so mature plants may be in clumps about 12" across. For this reason, it serves well as a border plant, as a common name suggests. However, it can be used very effectively as a ground cover for large areas if the divisions, also called "bibs", are sprigged.

L. spicata produces narrower, grassy leaves about 1/4" wide and up to 8" long. Evergreen foliage may be variegated. Unlike L. muscari, flowers are borne on much shorter spikes and may not even be visible above the foliage. Rhizomes of L. spicata tend to be longer, so the plant makes a very good ground cover, but does not serve so well as a border. Thus it is commonly known as "creeping lilyturf." It is fine for erosion control in medium-sized areas provided that water does not flow with such force that the plants are dislodged before established. L. spicata is cold hardy in USDA climate zones 4 through 4 through 10. Recommended soil pH is 4.5 to 6.0.

Prepare the planting bed for Liriope by cultivating at least 4" deep, removing all traces of weeds. Compacted soil should be cultivated to 8" deep. Composted manure may be incorporated into the soil. Fertilizer may be used. If you choose to do so, incorporate 10-10-10 fertilizer at a rate of no more 2 lbs. per 100 square feet into the top 4" to 6" of soil. Avoid synthetic fertilizers contacting any part of your plants.

Liriope can be planted any time you have a shovel handy, even bare root plants. It is tough, tough, tough. If you left them laying out on hot concrete all day long, I believe they would still survive.

Plant bare root divisions by punching holes in the soil with a trowel or dibble at 6" to 12" apart, and insert the plants, pressing soil around the roots as you go. Plants in small containers may be spaced 10" to 18" apart. Dig planting holes into the cultivated soil a little less deep than the depth of the growing container. Place the plants into the holes and back-fill. Press soil around the roots. Do not cover the root balls with soil. The tops should be slightly exposed. Add a top-dressing of mulch around the plants, not on top of them, about 2" deep. Irrigate thoroughly.

Maintenance is minimal. Liriope has few pest and disease problems, and tolerates poor soil. Cold weather may damage foliage, but annual spring mowing at a high mower setting will easily renovate. Liriope is deer resistant, but deer will eat almost anything if hungry enough.

Because it is so widely used, some folks think that Liriope is boring and over-used. But I don't agree. If someone asks me to recommend a low-maintenance, lush, evergreen ground cover or border for full sun to partial shade that tolerates a wide range of soil conditions, I ask, "Have you tried Liriope?"

Return to Liriope at goGardenNow.com.

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