By the HMNDP Editorial Team
Last reviewed: June 2026
What mondo grass is
Mondo grass (Ophiopogon japonicus) is an evergreen perennial groundcover in the lily family, not a true grass. It forms low clumps of stemless, dark green, grass-like arching leaves that stay green year-round in USDA zones 7 to 11. Gardeners use it as a shade-tolerant carpet or a tidy border. It spreads slowly by short rhizomes and is not classified as invasive.
Despite the name, mondo grass is more closely related to lilies and asparagus than to lawn turf. The “grass” label comes only from the narrow, blade-shaped foliage.
The plant produces small lavender to white flowers in summer, often hidden in the foliage, followed by metallic blue berries. Most people grow it for the leaves, not the bloom. If you are trying to identify an unknown blade-leafed plant in your yard, our guide to figuring out what kind of grass you have walks through the visual cues.
Mondo grass vs dwarf mondo grass vs liriope: the ID table
The single most searched confusion is telling these three apart. Standard mondo grass reaches 6 to 12 inches, dwarf mondo (Ophiopogon japonicus ‘Nana’ or ‘Gyoku-ryu’) stays 2 to 4 inches, and liriope (often called monkey grass) is a separate genus that grows taller, wider, and spreads faster. Use the table below to identify what you have or what to buy.
| Trait | Mondo grass (Ophiopogon japonicus) | Dwarf mondo grass (‘Nana’) | Liriope / monkey grass (Liriope muscari or L. spicata) |
|---|---|---|---|
| Mature height | 6 to 12 in | 2 to 4 in | 12 to 18 in |
| Leaf width | About 1/8 in, fine | About 1/16 in, very fine | 1/4 to 1/2 in, broader |
| Leaf color / habit | Dark green, arching | Very dark green, dense tufts | Green or variegated, stiffer, more upright |
| Flower | Small, lavender-white, hidden | Tiny, rarely seen | Showy lavender or white spikes above foliage |
| Berry | Metallic blue | Metallic blue | Black |
| Spread rate | Slow, clumping by short rhizomes | Very slow | Fast if L. spicata (running rhizomes); clumping if L. muscari |
| Typical spacing | 6 to 8 in apart | 4 to 6 in apart | 8 to 12 in apart |
Quick field test: if the flowers stand clearly above the leaves on visible spikes, it is liriope. If blooms hide inside the clump and berries are blue, it is mondo grass. Both are sold loosely as “monkey grass,” which is why labels alone fail.
Is mondo grass invasive or does it spread?
Mondo grass is not classified as invasive in the United States. It spreads slowly outward by short underground stems (rhizomes) and by enlarging clumps, gaining roughly an inch or two of width per year. It stays where you plant it and is easy to contain by edging or division. This is the key difference from spreading liriope.
The plant people worry about is Liriope spicata, a relative with aggressive running rhizomes that can colonize beds and lawns. Several state extension programs flag L. spicata as weedy. Standard mondo grass and dwarf mondo do not run that way.
If you want a slow-filling, well-behaved evergreen carpet, mondo grass is the safer pick. If you accidentally bought “monkey grass” that is racing across the bed, you likely have L. spicata, not mondo.
How far apart to space mondo grass and dwarf mondo grass
Space standard mondo grass 6 to 8 inches apart on center and dwarf mondo grass 4 to 6 inches apart. Tighter spacing fills in faster but costs more plants. At 6-inch spacing you need about 4 plants per square foot; at 4-inch spacing, about 9 per square foot. Plan around the table below for any size project.
| Type | Spacing on center | Plants per sq ft | Plants per 100 sq ft | Time to fill in |
|---|---|---|---|---|
| Mondo grass (fast fill) | 6 in | ~4 | ~400 | 1 to 2 seasons |
| Mondo grass (economy) | 8 in | ~2.25 | ~225 | 2 to 3 seasons |
| Dwarf mondo (fast fill) | 4 in | ~9 | ~900 | 2 to 3 seasons |
| Dwarf mondo (economy) | 6 in | ~4 | ~400 | 3 to 4 seasons |
Stagger plants in a triangular grid rather than straight rows for faster, gap-free coverage. Single plugs (from 2 to 3 inch pots) are the cheapest start; quart or gallon clumps cost more but fill in sooner because each clump can be divided.
What it costs to plant an area
Budget by plug count, not square footage. Mondo grass plugs commonly run $1 to $3 each at nurseries, and dwarf mondo plugs $2 to $5 each because they are slower to produce. A 100 square foot bed at 6-inch spacing (about 400 plugs) often costs $400 to $1,200 in plants alone, before soil prep.
You can cut cost sharply by buying a few gallon clumps and dividing them. One mature clump often splits into 6 to 12 plantable pieces, each with roots. This is the standard propagation method and explains why patient gardeners spend a fraction of the plug-by-plug price.
Sun vs shade: where mondo grass performs
Mondo grass is prized for shade tolerance and grows well in part shade to full shade. It also handles full sun in zones 7 to 9 if the soil stays moist, but harsh afternoon sun can scorch leaf tips and fade the dark green color. In hot southern climates, give it afternoon shade for the best look.
In deep shade where lawn turf fails, mondo grass is one of the most reliable evergreen groundcovers. For broader options when grass will not grow under trees, compare it against the alternatives in our overview of different grass and groundcover types.
Dwarf mondo handles shade equally well and is often used between flagstone and in deep-shade borders where its compact height reads as a fine green moss.
Can you walk on mondo grass or use it as a lawn substitute?
Mondo grass tolerates light, occasional foot traffic but is not a true lawn substitute for play areas or pets. Dwarf mondo grass handles foot traffic better and is the variety planted between stepping stones and pavers. Neither recovers from heavy daily wear the way Bermuda or zoysia turf does.
For a no-mow, low-traffic “lawn” look in shade, dwarf mondo planted as a solid carpet is the most popular choice. It needs no mowing and stays under 4 inches. Expect to keep heavy traffic on paths, not on the planting.
How to grow and care for mondo grass
Mondo grass care is low-effort once established. Plant in well-drained soil rich in organic matter, water regularly through the first growing season, then water only during drought. Fertilize lightly once in spring, and cut back tattered foliage before new growth appears. It rarely needs mowing or spraying.
- Plant in spring or fall into loose, well-drained soil amended with compost. Set clumps at the depth they grew in the pot.
- Water deeply once or twice a week for the first 8 to 12 weeks while roots establish, then taper to drought-only watering.
- Fertilize with a light feeding of slow-release lawn or all-purpose fertilizer once in early spring. See our notes on choosing the right fertilizer for blade-leafed plantings.
- Cut back ragged or winter-burned foliage in late winter to early spring, before new leaves emerge. Mow standard mondo on the highest setting or shear by hand; do this every 1 to 2 years, not annually.
- Divide overgrown clumps in spring to propagate and refresh the planting.
Mondo grass has few pests. Overwatering and poor drainage are the main causes of decline, leading to root rot. For more groundcover and lawn-care fundamentals, the HMNDP learn hub collects step-by-step guides.
Hardiness zones and where it grows
Mondo grass is reliably hardy in USDA zones 7 to 11, covering most of the southern and coastal United States. Dwarf mondo shares the same range. In zone 6 it may survive with winter mulch and a sheltered spot, but foliage can brown in hard freezes. North of zone 6 it is usually treated as a container or seasonal plant.
Frequently Asked Questions
What is the difference between mondo grass and dwarf mondo grass?
Both are the same species, Ophiopogon japonicus, but dwarf mondo grass (‘Nana’) is a compact selection. Standard mondo reaches 6 to 12 inches with leaves about 1/8 inch wide; dwarf mondo stays 2 to 4 inches with finer leaves and grows more slowly. Use standard mondo for borders and broad coverage, dwarf mondo between stepping stones and in tight, deep-shade spaces.
Is mondo grass the same as liriope (monkey grass)?
No. Both get called monkey grass, but they are different genera. Liriope (Liriope muscari or L. spicata) grows taller (12 to 18 inches), has wider leaves, showy flower spikes above the foliage, and black berries. Mondo grass is shorter, finer-leaved, has hidden flowers and metallic blue berries, and spreads more slowly. Liriope spicata also runs aggressively, while mondo grass clumps.
Is mondo grass invasive or does it spread?
Mondo grass is not classified as invasive in the United States. It spreads slowly by short rhizomes and widening clumps, gaining only an inch or two per year, and stays where planted. It is easy to contain by edging or dividing. The aggressive spreader people confuse it with is Liriope spicata, a relative flagged as weedy by several extension programs.
How far apart should you space mondo grass and dwarf mondo grass?
Space standard mondo grass 6 to 8 inches on center and dwarf mondo grass 4 to 6 inches on center. At 6-inch spacing you need about 4 plants per square foot; at 4-inch spacing, about 9. Tighter spacing fills in within one to two seasons but uses more plants. Plant in a staggered triangular grid for faster, gap-free coverage.
Does mondo grass grow in full sun or only shade?
Mondo grass grows best in part to full shade but tolerates full sun in zones 7 to 9 if soil stays moist. Harsh afternoon sun can scorch leaf tips and fade the dark green color, so give it afternoon shade in hot southern climates. In deep shade where turf grass fails, mondo grass is one of the most dependable evergreen groundcovers.
How fast does mondo grass grow and how long does it take to fill in?
Mondo grass grows slowly. At 6-inch spacing, standard mondo grass typically closes gaps in one to two growing seasons; at 8-inch spacing, two to three. Dwarf mondo is slower, taking two to four seasons depending on spacing. You can speed coverage by planting tighter, using a triangular grid, and keeping plants watered through establishment.
Can you walk on mondo grass or use it as a lawn substitute?
Mondo grass tolerates light, occasional foot traffic but is not a durable lawn substitute for play or pets. Dwarf mondo grass handles traffic better and is the usual choice between stepping stones and pavers. For a no-mow shade “lawn” look, a solid carpet of dwarf mondo works, but keep heavy daily traffic on paths rather than the planting.
How do you care for and maintain mondo grass?
Plant mondo grass in well-drained, compost-amended soil. Water deeply once or twice weekly for the first 8 to 12 weeks, then only during drought. Feed lightly with slow-release fertilizer once in spring. Cut back tattered or winter-burned foliage in late winter before new growth, every one to two years. Divide overgrown clumps in spring to propagate. Avoid overwatering, the main cause of root rot.