Monkey grass is a common name for a popular, low-maintenance perennial that provides a lush, grass-like appearance in gardens. It is valued for its toughness and ability to thrive where traditional turfgrass fails, particularly in shade. The term “monkey grass” causes confusion because it refers to two distinct, though closely related, genera with important differences in size and growth habit. Understanding these differences helps gardeners select the best variety for specific landscape needs.
Identifying the Two Main Types
The term “monkey grass” encompasses two different groups of plants, both native to East Asia: Liriope and Ophiopogon. Both genera are members of the Asparagaceae family and exhibit distinct characteristics that affect their use in the garden.
Liriope, commonly known as Lilyturf or Border Grass, is the larger and more vigorous type. It typically grows in zones 5 through 10 and is often used for creating defined borders due to its taller stature. Liriope muscari is a clumping variety, while Liriope spicata is an aggressive runner that spreads by rhizomes, suitable for quick ground coverage.
Ophiopogon, often called Mondo Grass, is smaller, denser, and has a finer texture than Liriope. This genus is slightly less cold-hardy, thriving in zones 7 through 11, and is known for its slow-spreading, dense mat-forming habit. Black Mondo Grass (Ophiopogon planiscapus ‘Nigrescens’) is a popular variety that provides a dark contrast in landscapes.
Defining Visual Characteristics
The foliage of monkey grass is its defining feature, consisting of long, narrow, arching leaves. Liriope leaves are typically wider, measuring between 1/2 and 3/4 inches, and the plant reaches heights of 12 to 24 inches. Cultivars like ‘Variegata’ feature creamy-yellow or white margins along the leaf edges, providing visual interest.
Ophiopogon foliage is finer and darker green, with leaves about 1/2 inch wide, reaching a mature height of 2 to 12 inches. The popular black Mondo Grass variety maintains a deep purple-black color throughout the year, offering a unique textural element. Most Liriope forms tight clumps, while Ophiopogon gradually spreads to create a dense, carpet-like groundcover.
Both types produce flower spikes in summer, though prominence varies. Liriope displays showy, upright flower spikes, often in shades of lavender, purple, or white, standing above the foliage. These flowers are followed by small, dark berries that persist into the fall and winter. Ophiopogon flowers are smaller, less conspicuous, and sometimes obscured by the leaves, typically appearing white or pale purple, followed by small blue berries.
Planting Requirements and Ongoing Maintenance
Monkey grass is valued for its resilience and adaptability, tolerating a wide range of growing conditions. Both Liriope and Ophiopogon prefer moist, well-drained soil and tolerate various pH levels. They are highly shade-tolerant, making them ideal for planting under trees, but most types also grow in full sun if they receive adequate moisture, especially in hotter climates.
Sun exposure influences the plant’s appearance and flowering success; plants in full shade may have reduced vigor and produce few or no flowers. Once established, monkey grass exhibits good drought tolerance, making it a low-water-use option. Consistent watering is necessary only during the initial establishment phase after planting.
Maintenance involves an annual trimming to remove old, tattered foliage before new growth begins. This is best done in late winter or early spring by shearing the leaves close to the ground. For spreading varieties like Liriope spicata, dividing the clumps every few years helps manage aggressive spread and maintain plant vigor. Minimal or no fertilizer is required.
Functional Uses in Garden Design
Monkey grass serves multiple practical roles in landscape design due to its dense growth and durability. Its most common use is as a reliable ground cover, particularly in shaded areas where turfgrass struggles. The dense foliage effectively suppresses weeds, reducing the need for constant weeding.
The plant’s clumping and spreading habits make it excellent for defining landscape edges. Clumping types, such as Liriope muscari, are frequently used as neat, tidy borders along walkways, driveways, or garden beds. Spreading types are effective for erosion control on slopes and embankments, as their robust root systems help anchor the soil against water runoff.
Cultivars offer textural and color contrast to surrounding plants, with the fine, dark leaves of Mondo Grass providing a sophisticated element. Dwarf varieties of Ophiopogon are sometimes used as a substitute for traditional turf in small, low-traffic areas or planted between pavers to soften hardscaping. Its evergreen nature ensures it provides structure and color throughout the entire year.