Mondo Grass (Ophiopogon japonicus) is a popular, low-growing perennial often utilized in landscaping as a textured groundcover or border plant. This plant is valued for its dense, grass-like tufts of dark green or sometimes near-black foliage, providing a strong color contrast in garden beds. It is an evergreen species in warmer climates and spreads slowly via underground runners, forming a thick mat that requires minimal upkeep once established.
Establishing the Plant
Successful planting begins with proper site selection, as Mondo Grass prefers filtered sun or partial shade, though some varieties can tolerate full sun if the climate is not excessively hot. Exposure to intense afternoon sun, particularly in warmer regions, can scorch the leaves and cause them to lose their vibrant color. The soil must be well-draining, as the plant’s root system is susceptible to rot in waterlogged conditions. Enriching the area with organic matter like compost before planting will enhance drainage and nutrient content.
When planting, dig a hole twice the width of the root ball, ensuring the crown sits level with the surrounding soil. Space individual plants 4 to 12 inches apart for dense groundcover, depending on the variety’s mature size. After positioning, backfill the hole, gently firm the soil, and water thoroughly to settle the roots and eliminate air pockets.
Routine Maintenance Schedules
Newly planted Mondo Grass requires consistent moisture to establish a strong root system, often needing water a few times per week for the first few weeks. Once the plants are established, their watering needs decrease significantly, and they show a degree of drought tolerance, though they perform best with weekly watering if there is no natural rainfall. It is generally better to water deeply and less frequently than to provide shallow daily sprinklings, which can encourage shallow rooting and fungal issues.
Mondo Grass is a light feeder and does not require heavy fertilization. An annual application of a balanced, slow-release granular fertilizer or compost in early spring is sufficient to boost color and growth. If foliage appears pale, apply granular fertilizer at a rate of about four tablespoons per four square feet, watering immediately to correct nutrient deficiencies. Because of its slow-growing nature, diligent weeding is necessary during the establishment phase until the Mondo Grass spreads densely enough to suppress most competing growth.
Addressing Specific Issues and Seasonal Tasks
One common issue to watch for is fungal root rot, often caused by the water mold Pythium splendens, which manifests as wilting and browning leaves due to overly wet soil. Ensuring excellent soil drainage is the primary preventative measure against this problem. Another occasional pest is the false oleander scale, which appears as small, disc-like insects on the underside of the foliage.
In colder climates, or if leaves are ragged after winter, the entire planting can be sheared or mowed down to about two inches in late winter or early spring before new shoots emerge. This removes old foliage and is an effective cultural control method for managing scale insects, provided trimmings are promptly removed and disposed of. Overly dense clumps can be divided in the early spring, with sections of eight to ten leaves and a generous root mass replanted to propagate new areas.