Mondo grass and monkey grass are common names that often get used for the same landscape plants, so the words alone do not reliably identify what is growing in a garden. In many places, “monkey grass” means liriope, while “mondo grass” means a plant in the genus Ophiopogon; checking the leaves, flowers, growth habit, and plant label is more useful than relying on the common name.
Why the Names Cause Confusion
Both plants are evergreen or nearly evergreen, grasslike ground covers used in borders, under trees, and along paths. They form clumps of narrow leaves and produce small flowers followed by berries. Their similar appearance, shared uses, and overlapping common names have blurred the distinction in everyday gardening language.
In botanical terms, liriope and Ophiopogon are separate genera in the asparagus family. Neither is a true grass: true grasses belong to a different plant family and have a different flower structure. “Monkey grass” is especially ambiguous because gardeners and regional references may apply it to liriope, mondo grass, or both. A label that gives the botanical name is therefore the clearest starting point.
- Liriope is often sold or described as monkey grass, lilyturf, or border grass.
- Ophiopogon japonicus is commonly called mondo grass, though it may also be called monkey grass in casual use.
- Ophiopogon planiscapus, including dark-leaved forms, is another plant often called mondo grass.
How to Tell Liriope from Mondo Grass
Look at several features rather than expecting one detail to settle the question. Cultivars vary, and a plant may not be flowering when you see it. Still, these clues can help distinguish the usual garden forms:
- Leaf width and texture: Liriope often has broader, more obviously strap-shaped leaves. Many mondo grasses have finer, narrower leaves, though some forms are comparatively robust.
- Flowers: Liriope commonly carries upright flower spikes above the leaves. Mondo grass flowers are often lower and less conspicuous within or just above the foliage.
- Overall habit: Liriope tends to make larger, more substantial clumps. Mondo grass is often used for a lower, finer-textured effect, but growth depends on the species and cultivar.
- Botanical label: “Liriope” or a name beginning with it identifies liriope; “Ophiopogon” identifies mondo grass. This is more dependable than a common name.
Flower color is not a foolproof test. Both groups can have pale flowers, and color may be hard to judge in shade or before flowers open. Likewise, leaf color alone does not identify a plant: green, variegated, and dark-leaved selections exist among the plants sold under these names.
Background and Garden Uses
Liriope and mondo grass became popular because they offer a tidy-looking layer of foliage where lawn grass may be difficult to establish or maintain. They are used as edging, as ground cover beneath trees, and to soften the edges of beds. Their leaves remain attractive for much of the year in climates where they are suited, and their small flowers and berries add seasonal interest.
These plants are not interchangeable in every design. A broad-leaved liriope can read as a more substantial border, while a fine-leaved mondo grass can create a softer, lower carpet. A dark-leaved Ophiopogon can add contrast against pale paving or green foliage. The best choice depends on the intended height, texture, spread, and local growing conditions—not simply on which name appears in a garden conversation.
They are also not a universal replacement for turf. Neither generally provides the walkable, mowable surface expected of a lawn. They are better treated as ornamental ground covers or edging plants, and their suitability depends on climate, soil, drainage, and the amount of light available.
Growing Conditions and Care
Many liriope and mondo grass varieties grow in partial shade, and some tolerate deeper shade. Many can also grow in sun where moisture and climate suit them, but full-sun performance varies. Check the requirements for the exact plant and compare them with the conditions in the planting site. A shaded bed beneath trees, for example, may be a good candidate, but tree roots can compete for water and make establishment slower.
Both groups generally prefer soil that drains reasonably well. Once established, some varieties tolerate periods of dry weather, but “drought tolerant” does not mean that newly planted clumps can be left without water. Watering needs depend on rainfall, soil, exposure, and the plant’s stage of establishment. Avoid keeping roots persistently waterlogged.
To establish a planting, space plants according to the mature spread stated on the label rather than packing them tightly for an instant carpet. Keep weeds down while the plants fill in, and water as needed while roots settle into the surrounding soil. Mulch can help conserve moisture and suppress weeds, but keep it from piling directly against the plant crowns.
Older foliage can look ragged after winter or become damaged. In some climates, gardeners trim or cut back foliage before fresh growth begins; in others, a light cleanup is sufficient. Avoid cutting so severely that new shoots are repeatedly damaged. The right timing and method depend on the local season and the plant’s growth pattern.
How to Choose for Your Yard
Start with the job the plant needs to do. For a low, fine-textured border, a compact mondo grass may fit better. For a fuller edge or a larger clump, a liriope selection may be more suitable. These are tendencies, not guarantees: mature size and spread differ among varieties, so read the plant label and allow room for growth.
- Match light: Note whether the site receives sun, partial shade, or deep shade, and choose a variety suited to that exposure.
- Check mature size: Compare expected height and spread with the edge, path, or bed available.
- Consider spread: Some selections expand into a broader patch, while clump-forming types remain more defined. Confirm the growth habit before planting.
- Think about maintenance: Consider whether you can reach the area to weed, trim, and divide plants if they become crowded.
- Use botanical names: When ordering or asking for a plant, use the genus and species or the full cultivar label when available.
For a small planting, buying a few well-spaced plants and allowing them to grow may be simpler than trying to create a dense cover immediately. For a large area, compare the mature spread and likely maintenance of each option before purchasing. The common name “monkey grass” alone is not enough information to make that comparison.
Common Problems and Misconceptions
A frequent mistake is assuming that all plants called monkey grass are the same. A gardener may recommend care for liriope while a neighbor is actually growing Ophiopogon. If a plant struggles, first confirm its identity, then review light, drainage, watering, and local climate rather than changing care based on the common name.
Another misconception is that these plants need no attention once established. They can still be invaded by weeds, become untidy, or outgrow a border. A planting may also look sparse for a while as it fills in. On the other hand, slow spread is not necessarily evidence of poor health; it may reflect the variety or growing conditions.
Do not assume that every plant sold as ground cover will stay within its intended boundary. Growth habits differ, and local conditions can affect spread. If containment matters, check the cultivar’s habit and monitor the planting. For a site near natural areas, ask a local horticulture service whether the selected plant is appropriate; what is suitable in one region may not be in another.
Frequently Asked Questions
Is monkey grass the same as mondo grass?
Sometimes the names refer to the same plant in casual use, but monkey grass is also commonly used for liriope. The name varies by region and seller. Check the botanical name: Ophiopogon indicates mondo grass, while Liriope indicates liriope.
Is liriope a type of mondo grass?
No. Liriope and Ophiopogon are different genera. They are related plants with a similar appearance and use in gardens, which helps explain why their common names are mixed up.
Which is better for shade?
Both include varieties that grow in partial shade, and some tolerate deeper shade. The best choice depends on the specific selection, the amount of light, soil drainage, and local climate. Check the plant label rather than assuming every variety has identical shade tolerance.
Will mondo grass or liriope replace my lawn?
They can cover soil in ornamental beds, but they are not generally a substitute for a lawn designed for regular walking and mowing. Choose a ground cover based on the site and intended use, not merely on its ability to spread.
How can I identify the plant I already have?
Look for a nursery label, purchase record, or botanical name. If those are unavailable, compare leaf shape, flower position, and growth habit, while remembering that these clues are not definitive for every cultivar. A local horticulture service may be able to identify a clear photograph or a specimen.
The Practical Answer
If you are deciding what to plant, do not treat “mondo grass” and “monkey grass” as precise alternatives until you know which species the seller means. Choose by botanical name, mature size, texture, light needs, and growth habit. If you are trying to identify an existing planting, “monkey grass” alone cannot settle it: it may mean liriope or mondo grass, depending on local usage.