Monkey grass, encompassing plants from the Liriope and Ophiopogon genera, is a favored groundcover in many landscapes. These evergreen perennials are appreciated for their grass-like foliage and adaptability. Understanding their root systems is important for successful planting and ongoing landscape management, as it helps in selecting the appropriate variety and implementing effective growth control strategies.
Understanding Monkey Grass Root Systems
Monkey grass varieties, primarily Liriope and Ophiopogon, exhibit distinct root system characteristics that influence their growth habits. Liriope muscari, often called big blue lilyturf, has a fibrous root system with scattered tubers, forming dense, slowly expanding clumps. These fleshy tubers can sprout new growth, but this type generally does not spread aggressively. Ophiopogon species, such as mondo grass (Ophiopogon japonicus), also typically grow in clumps with underground stolons and tuberous roots, forming a dense mat.
In contrast, Liriope spicata, known as creeping lilyturf, possesses a rhizomatous root system. Rhizomes are underground stems that spread horizontally, sending up new shoots and roots along their length. This enables Liriope spicata to spread rapidly and aggressively, forming a wide groundcover. Most monkey grass roots remain shallow, typically filling the upper 6 to 12 inches of soil.
The specific root type directly impacts the plant’s behavior in the landscape. Clumping varieties like Liriope muscari and most Ophiopogon species remain contained, making them suitable for defined borders or accent plants. Their fibrous roots and short stolons allow clumps to expand gradually without invading adjacent areas. Spreading varieties, particularly Liriope spicata, are better suited for covering large areas or slopes where their vigorous, mat-forming root system aids erosion control. However, their aggressive rhizomatous growth means they can quickly colonize unwanted spaces if not managed.
Managing Monkey Grass Root Growth
Effective management of monkey grass root growth begins with careful planting considerations, distinguishing between clumping and spreading varieties. For clumping types like Liriope muscari, appropriate spacing is important for their slow, gradual expansion. Planting these varieties about 1 foot apart provides sufficient room to fill in without overcrowding. These plants are well-suited for defining pathways or creating neat borders due to their contained growth.
Conversely, spreading, rhizomatous varieties such as Liriope spicata require containment to prevent unwanted colonization. Installing a root barrier at planting time is a common strategy. These barriers, often plastic or metal, should be buried at least 12 to 18 inches deep around the planting area, with a couple of inches left above the soil surface to deter rhizomes from growing over. Alternatively, growing Liriope spicata in containers effectively restricts its root spread.
For containing aggressive root growth in existing plantings, regular maintenance is needed. Periodically inspecting the perimeter of Liriope spicata beds and trimming back any spreading rhizomes helps. If removal of unwanted monkey grass is necessary, the approach depends on the root type. For clumping varieties, digging up the entire clump and its surrounding soil is effective. However, for rhizomatous types, hand pulling is often insufficient as roots and rhizomes can snap off, leading to regrowth.
A shovel or soil knife is more effective for removing spreading varieties. Any remaining roots or rhizomes can be suffocated by covering the area with plastic or landscape fabric. In cases of extensive spread, especially with Liriope spicata, a non-selective herbicide containing glyphosate may be used, though multiple applications on actively growing plants might be necessary.
Common Questions About Monkey Grass Roots
Monkey grass invasiveness depends on the specific type. While Liriope muscari is a clumping variety that generally stays contained, Liriope spicata spreads aggressively via rhizomes and is considered invasive in some regions, including parts of Virginia, Georgia, and North Carolina. Its vigorous spreading habit can allow it to escape cultivated areas and crowd out native plants.
Monkey grass roots are generally not a concern for potential damage to foundations or pipes. Their root systems are typically shallow, usually extending only 6 to 12 inches deep, and are not aggressive enough to penetrate intact concrete or plumbing. Tree roots, for comparison, exploit existing cracks, but monkey grass roots lack this destructive capability. When planting near structures, providing some space allows for air circulation and growth.
Monkey grass, particularly spreading varieties, is effective for erosion control. Their dense, mat-forming root systems anchor soil on slopes and prevent runoff, making them suitable for challenging landscape areas where soil stability is desired. The roots also absorb nutrients and water, contributing to the plant’s drought tolerance once established.