Mondo grass is the plant behind most of the neat dark green strips you see between pavers, along path edges and under established trees in Australian gardens. It is evergreen, needs no mowing, grows in shade where lawn fails, and holds its appearance year-round from Cairns to Hobart. It is also not a grass, and it is slower than almost anyone expects - two facts that between them explain most of the disappointment people have with it.
Quick facts
| Detail | What to expect in Australia |
|---|---|
| Botanical name | Ophiopogon japonicus |
| Family | Asparagaceae - a lily relative, not a grass |
| Height | 50-100 mm dwarf, 200-300 mm standard |
| Position | Part shade to full shade. Tolerates morning sun |
| Soil | Free draining, enriched with organic matter |
| Water | Regular. Not a drought plant |
| Growth rate | Slow - dwarf forms especially |
| Traffic | Light footsteps only |
| Best climates | Every Australian capital |
The three types
| Type | Height | Best for |
|---|---|---|
| Dwarf mondo | 50-100 mm | Between pavers, tight edging, lawn-look panels |
| Standard mondo | 200-300 mm | Mass planting under trees, borders |
| Black mondo | 150-200 mm | Contrast planting, feature pots |
Dwarf mondo is the one used between stepping stones and as a fine crisp edging - it stays low enough to walk over and never needs cutting. Standard mondo covers ground faster and suits mass planting under trees. Black mondo is genuinely near-black and works as a deliberate contrast against pale gravel, sandstone or silver foliage rather than as general groundcover.
The slow growth problem
Mondo grass spreads by short underground stems, and it does it slowly. Dwarf mondo in particular can take two to three years to close a gap that a fast groundcover would fill in one season.
That means the cost of a mondo planting is largely decided at installation. Plant at 100 mm centres for dwarf mondo if you want cover within a year or two; at 200 mm you will be weeding between plants for considerably longer. It is a plant where buying more upfront genuinely saves money and effort.
Where it works in Australian gardens
- Between pavers and stepping stones - the classic use. Dwarf mondo tolerates being stepped on occasionally and never needs trimming.
- Under established trees - it handles root competition and dry shade far better than lawn.
- Path and bed edging - gives a crisp dark green line that stays looking deliberate.
- Narrow strips beside a house - shaded, awkward to mow, and exactly where mondo excels.
- Japanese and minimalist gardens - the fine even texture suits restrained planting schemes.
- Pots - black mondo especially, as a textural filler.
Where it does not work
Mondo is not a lawn substitute for an area people actually use. It tolerates occasional footsteps between pavers, but children playing or a dog running on it will wear it out, and it recovers slowly.
It is also not drought tolerant. In full afternoon sun in Perth, Adelaide or inland Australia it browns off and looks poor without regular watering. Keep it to shaded and part-shaded positions.
Where it grows in Australia
Practically everywhere, which is one of its strengths. Mondo grass performs in Brisbane humidity, Melbourne and Canberra frost, Perth and Adelaide dry heat, and tropical Queensland, provided it has shade and water. It is evergreen in all of them, holding the same appearance in July as in January.
How to plant
- Plant in autumn or spring, avoiding extreme heat.
- Choose part or full shade. Morning sun is fine; hot afternoon sun is not.
- Improve the soil with compost. Mondo does better in soil holding organic matter than in bare subsoil.
- Space at 100 mm for dwarf mondo, 150-200 mm for standard, if you want cover within a couple of years.
- Plant at the same depth as it was in the pot - burying the crown causes rot.
- Mulch lightly between plants until they knit together.
- Water regularly through the first year.
Ongoing care
Almost none, which is the point. Mondo needs no mowing, no trimming and no shaping. Water through dry spells, apply a light controlled-release fertiliser in spring if growth seems slow, and remove any browned foliage by hand.
Established clumps can be lifted and divided in spring to expand a planting at no cost - the most economical way to cover more area, given how slowly it spreads on its own.
Common problems and fixes
- Browning or yellowing tips usually means too much sun or not enough water. Both are common in Perth and Adelaide.
- Bare patches from wear means it is being walked on too much. Mondo is not a lawn.
- Very slow spread is normal. Plant more densely rather than waiting.
- Rotting crowns comes from planting too deep or poor drainage.
- Weeds establishing between plants is the main maintenance issue in the first two years. Mulch and weed until the cover closes.
- Black mondo fading means too much shade - it needs some light to hold the dark colour.
Frequently asked questions
Is mondo grass actually a grass?
No. Ophiopogon japonicus belongs to the Asparagaceae and is more closely related to lilies. That is why it never needs mowing and spreads slowly by underground stems rather than runners.
How fast does mondo grass spread?
Slowly. Dwarf mondo can take two to three years to close gaps between plants. Plant at 100 millimetre centres for dwarf and 150 to 200 for standard if you want cover within a reasonable time.
Can you walk on mondo grass?
Lightly. Dwarf mondo tolerates occasional footsteps between pavers and stepping stones, but it will not take children playing or a dog running on it, and it recovers slowly from wear.
Does mondo grass grow in full sun?
It survives but does not thrive. In full Australian afternoon sun it browns off without frequent watering. Part shade to full shade gives much better colour and needs far less water.
What is the difference between mondo grass and liriope?
They look similar but liriope grows taller with broader leaves and showier flower spikes, and it tolerates more sun. Mondo is finer, lower and better suited to shade and to planting between pavers.
How do I make mondo grass spread faster?
Plant more densely at the outset, keep it watered and lightly fed, and divide established clumps in spring to expand the planting. There is no way to make individual plants grow quickly - it is simply a slow species.
Ready to plant?
We grow dwarf, standard and black mondo in quantities suited to mass planting. Browse our groundcover collection, or plants for partial shade.
Related reading: groundcovers for between steppers and the best groundcovers for shade.
