The common names used in landscaping often cause confusion, and “Mondo Grass” and “Monkey Grass” are a prime example. While both terms are frequently used interchangeably to describe a tough, grass-like groundcover, they refer to two separate groups of plants. This confusion stems from their similar appearance and shared utility in the landscape. Understanding the distinctions between these two genera is key to selecting the right plant for a specific gardening need.
Setting the Record Straight: Defining the Plants
Mondo Grass belongs to the genus Ophiopogon, typically Ophiopogon japonicus. Monkey Grass most frequently describes plants in the genus Liriope, including the clumping Liriope muscari and the spreading Liriope spicata. Both Ophiopogon and Liriope are low-growing, evergreen perennials native to Asia and belong to the Asparagaceae family. This shared family connection explains why they are often mistaken for one another.
Key Distinctions in Appearance and Growth Habit
A primary difference is the texture and width of their foliage. Mondo Grass (Ophiopogon) features finer, more delicate leaves that are narrow, generally measuring 3/16 to 1/4 inch wide. Conversely, Monkey Grass (Liriope) has a coarser appearance with wider, strap-like leaves that can reach up to 1/2 to 3/4 inch across. Mondo Grass is the shorter plant, usually forming a dense, low mat between 4 and 12 inches tall. Monkey Grass is noticeably taller, commonly reaching a height of 12 to 18 inches.
Growth patterns also provide a clear means of identification, particularly regarding root systems. Mondo Grass varieties form tight, tuberous-rooted clumps and spread slowly, making them easier to contain. While Liriope muscari forms neat clumps, Liriope spicata is known for its aggressive, spreading nature due to extensive rhizomes. The distinction between a plant that stays put and one that spreads rapidly is a major factor in landscape planning.
Flower and fruit production offer the most definitive visual separation. Mondo Grass produces very small, white to lilac flowers often hidden beneath the foliage. These flowers are followed by distinctive, pea-sized, glossy bright blue berries. Monkey Grass is showier, featuring prominent flower spikes that rise well above the foliage, resembling miniature grape hyacinths. These spikes bear clusters of purple or white flowers, which then develop into small, black berries.
Practical Landscape Applications and Care
The contrasting growth habits and tolerances lead to different ideal uses in the garden. Mondo Grass is suited for small-scale, precise applications where a neat, contained look is desired. It works well as a tidy border, between stepping stones, or in rock gardens where its slow-spreading clumping nature is an asset. Ophiopogon prefers shadier conditions and needs consistently moist, well-drained soil to thrive.
Monkey Grass, due to its greater vigor and size, is utilized for large-scale landscaping projects, especially in challenging locations. It is an excellent choice for mass planting, erosion control on slopes, and covering large areas beneath trees. Liriope is more tolerant of sun, heat, and drought, making it a reliable option for poor-soil or high-traffic areas.
Maintenance routines also differ substantially. Mondo Grass rarely requires a cutback because its foliage remains attractive through the winter. Conversely, Liriope often benefits from being cut back to the ground in late winter or early spring before new growth emerges. This annual shearing removes tattered, old foliage and prevents the spread of certain foliar diseases.