In recent years, ornamental grasses have become very popular for landscaping, and Mondo grass and Monkey grass are two species that are frequently used. These natives of Asia are often mistaken for each other, but once you know how they differ, it’s easy to tell them apart!
What’s the Main Difference Between Mondo and Monkey Grass?
The main difference between Mondo and Monkey grass is height. Monkey grass grows between 12-24 inches (30-60 cm) tall, with a spread of about 18 inches (45 cm), while Mondo grass tops out at 10 inches (25 cm), and there are dwarf varieties that only reach 2-3 inches (5-8 cm) tall.
The Differences Between Mondo and Monkey Grass
Appearance
Most Mondo grass and Monkey grass varieties are green, so it’s not that easy to tell them apart on the basis of colour. However, there are Mondo grass varieties that are so dark that they are almost black, while some Monkey grass varieties have striped variations (gold band).
The blades of Mondo grass and Monkey grass can help you differentiate between the two plants. Monkey grass has wider blades of ½-¾ inch (13-19 mm) than the Mondo grass width of ¼ inch (6mm). Monkey grass blades tend to stand fairly stiff and upright, while Mondo grass blades droop into a softer, rounder shape.
As mentioned before, height is the most obvious difference between these two ornamental grasses.
- Monkey grass can reach as high as 24 inches (60 cm) with a spread of 18 inches (45 cm),
- while Mondo grass doesn’t get much taller than 10 inches (25 cm) with a spread of 12 inches (30 cm),
- and dwarf Mondo varieties are only 2-3 inches (5-8 cm) tall and spread to 3 to 4 inches (8-10 cm) across.
Mondo grass spreads rapidly once it is established, and in fact can become invasive in warmer regions. When it comes to Monkey grass, it depends on which type you are growing. Liriope muscari is not invasive, but Liriope spicata can spread through underground rhizomes and become a problem under ideal growing conditions.
The flower spikes of the two species are easy to tell apart. The dark blue or purple spikes of the Monkey grass flowers rise up above the clumps of grass, while the white or pale mauve Mondo grass flowers are hidden within the blades. Mondo grass flowers in May and June, while Monkey grass flowers in August and September.
The flowers will set fruit, producing berries that differ between the species. Mondo grass berries are bright blue, while Monkey grass berries are black.
Winter Tolerances
There is a distinct difference in winter tolerances between these two ornamental grasses.
In regions where temperatures rarely fall below freezing, Monkey grass is an evergreen perennial, although if it gets nipped by cold spells it may need to be trimmed back to clean it up. However, in colder climates, the plants will die over winter.
On the other hand, Mondo grass is hardier and will survive winters with temperatures as low as -10°F (-23°C).
Sun and Shade Tolerances
While both Mondo grass and Monkey grass are recommended for shady locations, their tolerance for sun is not the same. Mondo grass will survive in full sun, but the deep green leaves will fade without some protection from the sun.
Thus, while Monkey grass can be grown in any light situation, Mondo grass is best planted in shade or semi-shade.
USDA Hardiness Zones
| Type | USDA Hardiness Zones |
| Mondo grass |
|
| Monkey grass |
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How Mondo Grass and Monkey Grass Similar
Growing and Care
Both Mondo grass and Monkey grass can be propagated by division, which is best done in early spring as they emerge from winter dormancy. Both should be divided every 1 to 3 years to prevent overcrowding. Trimming is only recommended once a year in late winter or early spring.
They both appreciate loose, well-drained soil with plenty of organic matter worked in to retain moisture without being soggy. Sandy soil drains water too quickly, while heavy clay will impede root development.
While they can handle some dry spells, regular weekly watering will keep them growing their best. They can be fertilized once or twice during the growing season with a balanced fertilizer.
Both species grow best between 65-75°F (18-24°C).
Mondo grass and Monkey grass will do best planted in locations with limited foot traffic. They can be planted as path edgings, or en masse on steep slopes or in wooded areas. They also can both be grown as container plants.
Read our related post “How Often Should You Water Mondo Grass?” here.
Read our related post “How Often Should You Water Monkey Grass?” here.
Quick Plant Comparison Table
| Mondo Grass | Monkey Grass | |
| Scientific Name | Ophiopogon japonicus | Liriope |
| Origin | Asia | Japan |
| Colors | Green or black | Green, or green with striped gold bands |
| Flowers | Pink, White | Purple, Violet |
| USDA Hardiness Zones | 7 to 11 | 5 to 10 |
| Dwarf Varieties | Yes | No |
| Size | Doesn’t get much taller than 10 inches (25 cm) with a spread of 12 inches (30 cm) | High as 24 inches (60 cm) with a spread of 18 inches (45 cm) |
| Winter Tolerances | Mondo grass is hardier and will survive winters with temperatures as low as -10°F (-23°C). | Can be trimmed back after cold spells, but will die in winter. |
| Heat Tolerances | Mondo grass will survive in full sun but will fade. Best grown in shade. | Best in shade, but Monkey grass can be grown in any light situation. |
The Verdict – Which Should I Choose for My Garden?
The choice between Mondo grass and monkey grass comes down to a few key factors.
First is your growing zone. Mondo grass and Monkey grass can grow in similar locations, however, Monkey grass can grow in USDA zone 5 unlike Mondo, but Mondo is actually a cold-hardy meaning it can tolerate a freeze better than Monkey grass. Monkey grass will go dormant in the winter and trimmings are required in late winter.
If you live in a region with consistently cold winters, Monkey grass is not the best choice for your garden. Even if the plants survive the winter, they may end up looking bedraggled by the time it’s over.
The next factor to consider is the growing habit of these 2 species. Monkey grass is taller with a much more upright habit, and its flower spikes put on a good show in late summer. On the other hand, Mondo grass is shorter, with a rounded shape, and the flowers are not prominent. Mondo grass also spreads much more aggressively. Dwarf Mondo grass is a great ground covering option for some.
If you want an ornamental grass as a specimen plant, rather than an overall ground cover, Monkey grass is probably the way to go. However, if you’ve got a problem spot such as a steep slope that you don’t want to have to mow regularly, Mondo grass will do a good job of filling it in quickly and providing long-term erosion control and reliable winter hardiness.
Ornamental grasses such as Mondo grass and Monkey grass are a great alternative to more labour-intensive turf grasses. While these two Asian natives have many differences, they are both tough plants that will thrive in a variety of different conditions. This makes them ideal to include as part of your landscaping plan.
Janice is a retired High School teacher who is spending her leisure years keeping busy with all sorts of projects. Aside from freelance writing, she’s an enthusiastic amateur chef, home wine maker, and tends a large raised-bed vegetable garden, while at the same time running a Bed & Breakfast.