The common name “Monkey Grass” is an informal blanket term used widely across the Southeastern United States for a group of popular, low-growing perennials. It is not a scientific designation for any single plant. This single term actually refers to two distinct, though closely related, genera often used interchangeably in garden design. Understanding the specific differences between these plants is necessary for gardeners to choose the right variety for their intended purpose.
The Genera Behind the Common Name
“Monkey Grass” refers primarily to two genera: Liriope (Lilyturf) and Ophiopogon (Mondo Grass). Both are native to East and Southeast Asia. Despite their grass-like appearance, they are not true grasses but belong to the Asparagaceae (Asparagus) family. Their similarity as groundcovers explains why the generic name “Monkey Grass” became widespread. The term is often applied specifically to the aggressive spreader, Liriope spicata (creeping lilyturf), but also includes the clumping Liriope muscari and various types of Mondo Grass.
Key Identifying Features
Both genera are classified as “grass-like” ornamentals, featuring dense clumps of evergreen, strap-like foliage that provides year-round color. These perennials grow from fibrous roots, often developing small, fleshy tubers that help them tolerate drought. In late summer, they produce small flower spikes followed by berries that persist into winter. While leaves are typically dark, glossy green, several cultivars offer variegated or black foliage. These shared visual traits make them excellent low-maintenance choices for borders and groundcover.
Distinguishing Liriope from Ophiopogon
The most noticeable physical distinction between the two genera is size and texture. Liriope muscari varieties are generally taller (12 to 18 inches) with wider, arching leaf blades. Ophiopogon japonicus (Mondo Grass) is significantly shorter and finer in texture, typically growing only 6 to 12 inches high. Differences also exist in their reproductive structures. Liriope species produce flower spikes that rise prominently above the foliage, displaying white or lavender-to-purple blooms, followed by black berries. Mondo Grass flowers are shorter and often hidden beneath the leaves, with subsequent berries being a distinct blue color. The growth habit also separates them: Liriope muscari is clumping, spreading slowly by short stolons, while Liriope spicata spreads aggressively via underground rhizomes.
Practical Landscaping Applications
The varying growth habits of these plants dictate their most appropriate uses in the landscape. Clumping varieties, such as Liriope muscari, are best suited for creating neat borders, edging sidewalks, or planting around foundation beds. Their controlled spread ensures they stay within defined areas. Spreading species, like Liriope spicata and many forms of Mondo Grass, are better utilized as large-scale groundcover for erosion control on slopes or filling in difficult-to-mow areas.
Both plants are highly valued for their resilience, thriving in conditions from full sun to deep shade and tolerating poor, well-draining soil once established. Their low-maintenance nature makes them a durable and effective landscape solution.