Variegated liriope, often known as lilyturf or border grass, is a popular ornamental plant. Its grass-like foliage, often striped with creamy white or yellow, and its purple or white flower spikes add visual interest to gardens. Gardeners frequently use this plant as a groundcover, for edging along pathways, or in mass plantings. However, its vigorous growth and ability to spread often raise concerns about invasiveness, prompting a closer look.
Understanding Variegated Liriope’s Growth
Variegated liriope (`Liriope muscari ‘Variegata’`) exhibits a clumping growth habit, forming dense mounds of foliage. It expands primarily through short underground rhizomes, unlike the aggressive runners of some other species. This means the plant gradually increases in size, staying in a more contained area and slowly expanding its clump. A mature clump of `Liriope muscari` typically spreads 12 to 18 inches wide.
In contrast, `Liriope spicata`, another common liriope species, is known for its rapid, aggressive spread via long rhizomes. This difference in rhizome length is a key distinction between the two species. While `Liriope muscari` and its variegated cultivars like ‘Variegata’ maintain a more compact, clumping form, `Liriope spicata` can quickly cover large areas, even growing beneath concrete and emerging on the other side. This difference in spread influences their garden behavior.
Clarifying “Invasive” in a Garden Context
The term “invasive” has a specific ecological definition: a non-native species that causes or is likely to cause environmental or economic harm, or harm to human health. Such plants spread aggressively, outcompeting native species and disrupting natural ecosystems. Variegated liriope (`Liriope muscari ‘Variegata’`) is not considered ecologically invasive in most of North America. It is not known to escape cultivation or establish wild populations that threaten native flora.
Instead, variegated liriope is more accurately described as an “aggressive spreader” or “vigorous grower” within a garden setting. It can spread quickly and potentially outcompete other plants in a cultivated bed if not managed. This distinction is important: an aggressive garden plant might require management, but an ecologically invasive plant poses a broader threat to natural habitats. Local environmental conditions and specific cultivars can influence a plant’s behavior, but `Liriope muscari ‘Variegata’` falls into the category of a well-behaved, though vigorous, garden plant.
Managing and Containing Variegated Liriope
Gardeners can manage and contain variegated liriope. One straightforward method is division. The best time to divide clumps is in late fall or early spring, before new growth emerges. To divide, dig up the entire clump, then use a sharp spade or knife to cut the root ball into smaller sections, each with foliage and roots. This process controls size and provides new plants for other garden areas.
Regular maintenance helps containment. Trimming the borders of liriope plantings prevents unwanted expansion. For more rigorous control, installing a physical root barrier around the planting limits its spread. Choosing appropriate planting locations is beneficial; using variegated liriope as a border plant or in contained areas, like along sidewalks or in dedicated beds, prevents it from encroaching on other plants. Proactive management ensures this attractive plant remains a desirable landscape feature.