If you’re looking for an eye-catching species to use as a border, lawn alternative, or specimen plant, mondo grass is an excellent candidate. Also known as monkey grass or lilyturf, this plant’s lush profusion of grass-like leaves, as well as its graceful flowers and colorful berries make it popular for a variety of uses.
Easy to propagate and tolerant of a wide range of conditions, it’s a good choice for beginning gardeners. There are several types of mondo grass, so before you buy, spend some time getting to know which one will give you the results you want.
Mondo Grass Basics
The term “mondo grass” refers to several species of evergreen perennial groundcovers native to Southeast Asia. Although they look like grasses, they’re actually members of the lily family (Liliaceae) or, in some more recent classifications, members of the asparagus family (Asparagaceae). The plant grows in clumps and spreads by sending out underground stolons (runners) and rhizomes (tuberous roots), but you can also propagate it by division.
Mondo grass (Ophiopogon genus) is often confused with Liriope (Liriope genus) because plants in the two groups are so similar in appearance and growth habits. The common names “monkey grass” and “lilyturf” are used for plants in both genera. To make sure you get the plant you want, always check the Latin botanical name. Three types of mondo grass are commonly available.
Mondo grass (Ophiopogon Japonicus) – The standard and most common mondo grass variety, this plant averages around 6 to 10 inches high and can reach 15 inches across. In summer, stalks of tiny, bell-shaped lavender flowers rise from its deep green leaves and produce a faint, sweet scent. The flowers are followed by cobalt blue berries. This plant does well in USDA zones 7 to 10 and is cold hardy down to -10 degrees. Even in near-freezing weather, its leaves stay green. While it can survive milder winters in zone 6, it won’t make it through colder ones.
Dwarf mondo grass (Ophiopogon Japonicus ‘Nanus’) – This small variety grows between 4 to 6 inches tall and around 8 inches wide. It puts out white or lavender flowers and blue berries. Beyond its size and flower color, it’s otherwise similar to standard mondo grass.
Black mondo grass (Ophiopogon planiscapus ‘Nigrescens’) – Although it’s a different species from standard mondo grass, this plant has similar growth habits and care requirements. It’s best known for the purplish-black color of its leaves, but the pink flowers it produces are an added benefit. It’s also larger than the other common mondo grass varieties, growing up to 12 inches high and 12 to 24 inches across.
Giving Mondo Grass a Place in Your Garden
Mondo grass owes a large part of its popularity to the variety of ways it can be used. For dwarf mondo grass, groundcover is the most common use. It’s an ideal lawn alternative if you want lush green grounds without the hassle of maintaining turf grass. Once a few plants are in place, they spread to create a lawn-like cover. This variety is a notoriously slow grower, though, so your lawn will take a few years to fill in.
It’s perfect for areas of deep shade and can even grow under black walnut trees. It’s also well suited to slopes where grass doesn’t grow well. Mondo grass is a traditional groundcover in Japanese gardens, where it’s planted around stepping stones and statues, under trees, and in flowing shapes around gravel beds.
Because it stops growing at a low height, you won’t need to — and, in fact, you shouldn’t — mow it. The downside is that mondo grass is more delicate than turf grass.
Dwarf mondo grass can tolerate being walked on every now and then, but regular foot traffic will destroy it. If you’ll need to walk through an area planted with mondo grass, install stepping stones or another type of path.
The plant is moderately pet-friendly. While it can stand up to dogs running and playing, it doesn’t handle their digging or urinating as easily. That said, it still tends to fare better than most turf grass.
Because it’s small and slow growing, dwarf mondo grass performs well as a houseplant. Plant it in well-draining potting soil or potting mix and place it in a shady or partially shady spot.
Standard-sized and black mondo grass are more often grown as ornamental plants. As edging plants, they create soft, informal borders between garden beds and the lawn or walkways. Their medium height helps them hold back plants in a planting bed without overwhelming them. Mondo grass is especially useful if you need an edge that’s wider and higher than the one you’d get with strip or masonry edging.
As an ornamental plant, mondo grass’ fountain of deeply colored leaves and the soothing sound they make as they rustle in the wind makes the plant a pleasant addition to seating areas. The flowers tend to get lost among the leaves, so they’re not a major reason to grow the plant.
All mondo grass varieties have good salt tolerance, allowing them to thrive in coastal gardens. Because the plant does well in the shade of trees and deer tend to avoid it, it’s a good pick for gardens in forested areas.
Mondo Grass Care Requirements
Mondo grass is easy to care for once established, but getting it established takes some preparation. In most climates, it can grow in anything between full sun to full shade, but it thrives in filtered sunlight. The more sun the plant gets, the lighter the leaf color will be. In a hot climate, though, a shady location is a must. Choose a location with well-draining soil or improve the soil drainage by working in 3 or 4 inches of organic matter such as compost or well-rotted manure.
It’s possible to grow the plant from seed, but most gardeners buy packs of plugs for a quicker start. Small plug plants can be planted as they are. If you’re propagating a larger plant, separate the plant into groups of two to four stolons. Plant standard and black mondo grass 6 to 12 inches apart and dwarf mondo grass 2 to 4 inches apart, depending on how fast you want the area covered. Through propagation by division, it’s possible to create an entire border from just one plant, although it will take years.
The only thing mondo grass is truly picky about is watering. Water it when the soil becomes dry down to 1 inch, which is usually once or twice a week in a moderate climate. Aim to keep the soil slightly moist during dry weather, but don’t let it become oversaturated because this plant doesn’t appreciate soggy feet. In general, mondo grass tolerates underwatering better than overwatering.
Mondo grass needs little fertilizing and often does well with none at all. It’s usually enough to apply a slow-release 10-10-10 fertilizer formulated for trees and shrubs once a year in early spring.
Mondo grass isn’t especially prone to pests or disease, but watch out for slugs and snails in damp, cool periods and fungal infections in damp, warm periods. Root rot, caused by the pathogen Pythium splendens, is one of the most common problems and brown leaf tips are usually the first sign. You might also notice the top of the plant is easy to pull away from the roots. To treat the condition, apply a fungicide formulated for this pathogen and topdress the soil with organic matter.
In spring, trim off any dead or broken leaves to keep the plant looking neat.
This plant spreads slowly, but it does spread, so you’ll need to do a little work to keep it in check. To keep it in a defined area, install strip edging or other edging material around it. For single plants or small groups, control their size by dividing the clump every three or four years in early spring. To do this, dig up the plant, taking care to unearth as many of its tuberous roots as you can, and gently pull the clump apart. Replant the new clumps where you want them. To corral daughter plants that have sprung up outside the main planting area, simply dig them up and replant them elsewhere.
Mondo grass isn’t a slow-grower everywhere, though. In the warm, humid Southern U.S., it flourishes so well it can easily become invasive. If you live in the South, talk with a plant nursery worker about mondo grass’ growth habits in your area.
As a lawn alternative, dwarf mondo grass can give you a lush expanse of green with less effort than turf grass and many other groundcovers. Standard and black mondo grass work well for a garden bed border that’s striking enough to stand out, but won’t detract from your flowers. Even a single mondo grass plant in an urn planter can dress up a dull corner of the garden.
Start your mondo grass off with the right light and soil conditions, take care with watering, and the plants should do well with minimal extra attention.
