Dwarf Mondo Grass (Ophiopogon japonicus ‘Nana’) is a dense, grass-like groundcover. It has narrow, arching, dark green leaves that form compact tufts, typically reaching a height of only four to six inches. This plant is often selected as a low-maintenance, no-mow alternative to turf in shady areas where traditional grass struggles. Uses include softening the edges of garden beds, creating borders, or filling the spaces between stepping stones and pavers.
Site Preparation and Initial Planting
Dwarf mondo grass thrives best in partial to full shade conditions. While it can tolerate some morning sun, intense afternoon sunlight, especially in warmer climates, causes browning or scorching. The soil must be well-draining, as the plant is prone to root rot in waterlogged conditions, but it prefers a consistently moist environment. Amending the planting area with organic matter, such as compost, helps achieve the ideal balance of drainage and moisture retention.
The preferred soil composition ranges from slightly acidic to neutral, ideally with a pH between 5.0 and 6.5. When preparing the soil, loosen it to a depth of about six inches, incorporating the organic amendments throughout the area. Planting is most effective when done in early spring or fall, allowing the plant time to establish its root system before the stress of summer heat.
Individual clumps should be spaced approximately four to six inches apart. When placing the plants, ensure that the crown—where the leaves emerge from the roots—is positioned level with the surrounding soil surface. Be careful not to bury the crown too deeply. After planting, water the area thoroughly until the soil is saturated to encourage the roots to take hold.
Essential Ongoing Maintenance
Consistent moisture is necessary for newly planted dwarf mondo grass, requiring the soil to be kept damp during the first year of establishment. Once established, the plant is more tolerant of short periods of drought, but regular irrigation results in lusher foliage and faster spreading. Water established plants when the soil is dry to a depth of about three inches.
Dwarf mondo grass is not considered a heavy feeder. If the plant shows signs of poor growth or pale foliage, apply a light application of a slow-release, balanced granular fertilizer, such as a 12-4-8 mix, in the early spring. Sprinkle the fertilizer around the base of the plants, taking care to brush any granules off the foliage to prevent leaf burn.
The plant benefits from an annual tidy-up to remove spent and damaged leaves. The best time for this rejuvenation is in late winter or early spring, just before new growth begins. The entire patch can be trimmed or mowed down to about one inch using a sharp mower blade set high. For small areas, use shears.
Addressing Common Growth Issues
The most frequent problem is fungal root rot, resulting from poor soil drainage or excessive watering. Symptoms manifest as yellowing leaves or a scorched appearance, indicating the roots are suffocating from lack of oxygen. Ensuring the soil is consistently moist but never standing in water is the most effective preventative measure.
Environmental stress can also cause the foliage to become discolored. Browning or yellowing of the leaf tips is a common reaction to intense afternoon sun or severe drought. Though generally pest-resistant, the plant’s succulent nature can attract slugs and snails, which chew holes in the leaves. These pests are managed by hand-picking them off the plants, especially after rain, or by using commercial baits.