Mondo Grass (Ophiopogon japonicus), often utilized as a low-maintenance ground cover, is a popular choice for gardeners seeking year-round foliage. This plant is a true perennial, belonging to the lily family rather than being a true grass. It is considered an evergreen species, meaning it maintains its green, grass-like leaves throughout the winter season. This characteristic makes it valuable for providing consistent color and texture in the landscape when many other plants have died back.
Defining Evergreen Status in Mondo Grass
Mondo Grass retains its foliage due to its structure and growth habits. Unlike deciduous plants that shed their leaves annually, Mondo Grass keeps its narrow, linear blades for more than one growing cycle. The plant achieves this longevity by investing energy into a robust, tuberous root system and underground horizontal stems called stolons. This underground network ensures the plant’s survival and supports the persistent above-ground foliage.
In consistently warm climates, such as the southern parts of its hardiness range, the foliage remains a vibrant, dark green throughout the year. The plant never enters a state of true dormancy where all growth ceases. Instead, it simply slows its growth rate during the cooler months, continuing to photosynthesize at a reduced level.
In the cooler parts of its hardiness range, cold stress can compromise the evergreen appearance. Temperatures dipping below a certain threshold can cause the leaf tips to brown or become ragged, often called winter burn. This discoloration is a physical depreciation of the older foliage, not a sign the plant has died. The plant’s crown and root system remain alive and dormant beneath the soil surface, ready to push out new, fresh growth in the spring.
Gardeners often trim back this ragged, older foliage in early spring. This encourages a flush of uniformly healthy, new blades. The plant’s survival mechanism prioritizes its perennial nature, ensuring survival even if the foliage is not pristine in late winter.
Ideal Growing Conditions and Hardiness Zones
The year-round performance of Mondo Grass is significantly influenced by the environment. This perennial thrives best within USDA Hardiness Zones 6 through 10, though some varieties may tolerate Zone 5 with adequate winter protection. Planting within these zones supports its evergreen habit.
Mondo Grass prefers partial to full shade, especially in hotter climates where intense afternoon sun can scorch the foliage. In cooler regions, it can handle more sun exposure, but dappled shade promotes the deepest green color. This plant is highly adaptable to various soil types, but excellent drainage is non-negotiable.
The plant’s root system, which consists of small tubers, is susceptible to rot if left in consistently saturated soil. Optimal growth occurs in moist, rich, well-drained soil with a slightly acidic to neutral pH. Once established, Mondo Grass is moderately drought-tolerant, but regular watering during the first growing season is necessary to encourage a deep, healthy root system. Minimal feeding is required, with an annual application of a balanced, slow-release fertilizer in the spring being generally sufficient to support its health.
Common Varieties and Aesthetic Differences
Standard Mondo Grass (Ophiopogon japonicus) is characterized by deep green, arching foliage, but several cultivars offer variations in size and color. These differences allow the plant to be used in diverse landscape applications. Standard Mondo Grass typically reaches a height of 8 to 16 inches and spreads slowly to form a dense sod.
Dwarf Mondo Grass (Ophiopogon japonicus ‘Nana’) is a compact option, growing only 2 to 4 inches tall. This miniature size makes it popular for planting between stepping stones, as a small-scale lawn alternative, or for creating a neat, moss-like effect in rock gardens. Its fine-textured, dark green leaves maintain the same evergreen quality as the standard species.
The most visually striking variety is Black Mondo Grass (Ophiopogon planiscapus ‘Nigrescens’), favored for its near-black foliage. This variety provides a dramatic contrast to lighter green or variegated plants and grows to about 6 to 12 inches high. The dark coloration is inherent and retained year-round, though it can appear slightly greener if grown in deep shade. Other less common cultivars include variegated forms that feature white or yellow stripes along the length of the leaves.