Mondo grass is one of the easiest and versatile ornamental grasses you can possibly plant in the garden.
This grass needs nearly no maintenance once it’s established.
It’s drought tolerant, deer resistant, and even tolerates salty soil.
Monkey grass has dark green foliage, but can also be lime green depending on sun exposure. There’s even a dwarf variety that’s purple-black.
It even blooms in season. And it fruits- but you can’t eat it.
Some types of mondo grass are tall- reaching up to 12 inches in captivity. Others are dwarf, which only get up to 3 inches or so. You can even replace your lawn with it.
It can be used for nearly everything- from plant cover to hide those ugly parts of your garden to filling the spaces between the gaps.
You’ll be glad to know that you can grow monkey grass in a wide range of hardiness zones. If you’re reading this and your local climate is relatively warm, mondo grass is for you!
Let’s learn about how to grow and care for this pretty ornamental grass.
(Background of featured image by By Loadmaster, Own work, CC BY-SA 3.0, .)
Guide Contents
Quick care guide: Mondo grass
| Plant type | Perennial grass |
| Origin | Southeast Asia |
| Scientific name | Ophiopogon japonicus |
| Other names | Lilyturf, monkey grass, black mondo grass. |
| Soil type | Organic, rich, loamy, peaty, sandy, clay, loose |
| Soil pH | 5.5-6.5 (slightly acidic) |
| Sunlight requirement | Partial sun, full sun (for lighter coloration) |
| Bloom season | Summer |
| Colors | Dark green, lime green, purple, variegated, blue, yellow, white, red, black |
| Max height | 16 inches |
| Max width | 14 inches |
| Low temperature tolerance | -10F |
| High temperature tolerance | 90F |
| Ideal temperature range | 60-70F |
| Humidity | Moderate (50% or higher), spritz with water if needed to bump it |
| Watering requirements | 1-2 inches per week, adjust for rain or drought, established grasses require less water |
| Fertilizer requirements | Balanced, slow release granule plant food in early spring before growing season |
| Plant food NPK | 10-10-10 |
| Days until germination | 14-180 days |
| Days until harvest | Not harvestable, seeds can be collected from the fruit |
| Bloom time | March, April, May, June, July |
| Speed of growth | Very slow |
| Hardiness zones | USDA hardiness zones 3-10 |
| Plant depth | From seeds: 0.5 inches From divisions: Same depth as root ball, 3 inches wide, 5-6 inches deep From seedlings: Same as original plant's depth to reduce shock |
| Plant spacing | 12-18 inches for large varieties; 3-5 inches for dwarf grasses |
| Plant with | Impatiens Begonia, ferns Blue fescue Heuchera Liriope Hostas Chartreuse plants Hakone grass New Zealand flax Primrose plants Stachys byzantina Cornus alba Perata cylindrica Helleborus Other mondo grasses |
| Don't plant with | Plants that have opposing care requirements |
| Propagation method | From seed, dividing root balls, seedling transplants |
| Common pests | Snails, slugs |
| Common diseases | Pythium root rot, leaf spot, blight |
| Indoor plant | No |
| Outdoor plant | Yes |
| Grown in container | Yes |
| Flowering plant | Yes |
| Beginner friendly | Yes |
| Care level | Minimal to none (Easy to care for once you get the hang of it, good for beginners) |
| Best uses | Pathing, bordering, void fill, lawn cover, lawn substitute, flowerbeds, streams, rivers, ponds, shady zones, stepping stones, zen gardens, creeping grass, fencing, turf replacement. |
What’s mondo grass?
Mondo grass, also known as monkey grass or lilyturf grass, is one cool plant.
This weirdly named grass is a low-hanging, mounding grass that is perfect for covering up ugly voids in your garden.
While it’s not obvious, it’s also very easy to care for and requires little to no care once established.
While not true grass, these perennials look like dense, clumped bunches of thin narrow leaves. They can be lime green to black and are extremely low maintenance. They’re actually a type of lily, part of the Ophiopogon genus.
They can cover up a large part of your yard, even with just a few plants. The leaves provide plenty of shade for shorter plants. The evergreen blades of grass look great in bright light.
These plants also bloom bell-shaped flowers in the summertime. And they produce black or blue berries from said foliage.
How’s that for decor? Mondo grass is a gorgeous evergreen with tubercle runners. If you’re looking for one of the easiest ornamental grasses in existence, mondo grass does the trick.
Types of mondo grass
If you’re having trouble deciding which type of mondo grass to plant, there are quite a few. This list will narrow it down to the most popular mondo species:
- Black beard (large, dark, ornamental grass, lavender flowers, blackberries, resilient, big foliage, good for zones 7-10)
- Nana (hardy in zones 6-11, tiny blue flowers, smaller compact size, dark green foliage)
- Nigrescens (dwarf size, dark black with white flowers, purple fruit, hardy in zones 5-10, likes light)
- Mondo “Japonicus” (popular classic, low maintenance, blue/white flowers, dark green foliage, bright blue berries, easy to grow, hardy in zones 6-12, elegant arching grass)
- Dwarf mondo grass “Nanus” (slender leaves, petite, compact, 2-4 inches max height, good for lawns)
Depending on your local environment, some will be much more suitable than others. Do your own research to see what’s good to grow in your zone.
How to propagate
Propagating mondo grass is super easy. It’ll remind you of the science experiment plants you grew in a cup in elementary school.
Those were the days, right? Did you do those mealworm in a cup experiments as well?
The ideal time to plant it is in the springtime when the temperatures pick up, rather than the cooler wintertime when it may have trouble germinating.
There are multiple ways to propagate mondo grass. Let’s cover the two most common techniques.
Starting from seed
Growing mondos from grass is rewarding but take quite some time to get that full look. If planting from seed, be aware that they’re extremely finicky.
They have poor germination rates and they take a long time to do so. Plus, they can end up not being true. They are mixed or hybrid plants. This makes them difficult to deal with.
Seeds can be harvested from the fruit of previous plants. Or they can be bought. But note that seeds you buy generally have lower germination rates unless the nursery is reputable. It’s hard to get quality seeds.
Plant the seeds in sterilized potting soil. You can bake the soil to remove all pathogens. They’ll also need a cold frame to germinate. Water and keep it humid.
Sow seeds just under the soil line- 0.5” deep. Thin to the strongest plant when the first pair of true leaves emerge. The soil should be moist, but never wet. Don’t let it dry out between watering.
Mondo grass seeds will randomly germinate. It takes anywhere from 14 days up to 180 days. This is why using regular mondo grass propagation from division is easier. This is not for the impatient.
From plant division
Plant vision is easily done. You divide up the side shoots. Or you can use large clumps using a clean pair of pruners. Do this in the springtime when the plant is actively growing.
Do NOT do this during the winter when it’s cold. You reduce the possibility of rooting. Diving this way is preferred because it’s reliable. You get exactly what you sow. The new mondos are the same as the host plants. This creates that uniform look in your garden.
To divide mondo grass, get a clean pair of scissors, pruners, or a knife. Sterilize it with rubbing alcohol.
Next, get your favorite garden spade. Gently dig around the soil and remove the dirt. When you can see the tuberous root entanglement at the base of the plant, gently use the spade to uproot it.
Remove excess dirt or debris using your fingers. Not with something too sharp.
You can wet it first to help loosen the roots. The roots can be extremely fragile, so be careful. Don’t use a sharp object if possible. If you damage it, you’re losing valuable tubercles that could root your new plants!
Get your sterilized pruners or knife. Cut the roots into equal sections. Each section should include at least 8 leaves with tubers and roots. This will maximize the chance of successful rooting.
If you want to use rooting hormones (gels or powders), use them now before you plant! Some popular choices are the following (links t0 Amazon):
You can use them to feed the roots if you’re having trouble getting nutrients from the soil.
Gently loosen the soil around the root ball and then pull the roots away. Pull upwards until it snaps. Each plant shoot should break apart easily.
The shoots should have a few roots on it when you separate them from the main plant’s root ball. This is why mondo grass is so easy to propagate. No need for special this or that.
Plant each side shoot into its own container. You can use 5-inch pots filled with some quality potting mix that’s well draining. Or you can plant them directly into the garden if you want to avoid moving them later on.
Just make sure that the soil you use is going to be the permanent one. Don’t change it later on as they don’t like plant shock.
If planting outside, place them in a sheltered area away from direct sunlight, draft, winds, or scorching sunlight. It should be well drained with rich, organic soil. Afternoon shade is recommended with dappled sunlight throughout the day. The morning sun is OK.
Water regularly following the watering regimen for mondo grass outlined below.
If planting in pots, water generally the first time around so the water pathways are established. Keep them moist, but never wet. When the root balls start to put on some new growth, it’s time to put them into the garden! Do this when the winter is over.
How to care for mondo grass
This section goes over some basic growing tips for mondo grass. You’ll see that it’s extremely easy to grow and care for, as long as you’re in the right zone.
Otherwise, you may need to make some changes to accommodate for temperature swings (such as adding mulch to keep it warm).
If you still have questions about how to grow monkey grass, feel free to post a comment using the form at the end of this page.
Hardiness zone
Mondo grass is an evergreen that is hardy in USDA zones 5-10. If you’re situated in these zones, you should be good to go. The plant is resilient once established.
It can tolerate salt, drought, rabbits, deer, and even light flooding (but not for extended periods or else you risk fungal issues for your grass).
Even if you’re outside of these zones, you can still grow mondos if you adjust for the season.
The plant is hardy to both hot and cold weather when the roots are established.
Soil
The soil must be well draining and supplemented with compost or manure if the soil column has poor nutrient flow. It should be free of debris, balanced NPK, and not tough because the root ball of mondo may have a hard time breaking through the soil to grow.
Put in some organic matter and some bone meal for extra nutrients. They love their bone meal. Get a pack of organic bone meal and go crazy.
It helps them build strong roots and should be used right at the soil line with the crown. Note that the crown should be placed just below the soil line.
If you’re planting mondo in containers, use a line of pebbles at the base of it.
This helps improve range and prevents it from clogging at the base. For the actual soil, use humus-rich soil with moisture retaining properties.
Supplement with peat moss, coconut coir, peat moss, or humus itself. Vermiculite can also be used. Bone meal can be used in both potted or soil sown mondo plants.
Soil pH
Mondos appreciate slightly acidic soil conditions with a pH range of 5.5-6.5.
If your soil is too basic or neutral, use peat moss or other soil amendments to lower the pH naturally. pH won’t make or break your mondo grass, but it’ll help them thrive.
Use composted or aged manure to help increase the nutrient density of the soil. You can measure your soil pH using a pH test kit (check them out on Amazon).
These are widely available and cheap to buy. You can get them in your local nursery or online.
Depth
Plant seeds 0.5 inches deep if starting from seed. If dividing, plant each cutting of the root ball to the same depth as the original plant’s root ball. Try to plant it in the same growing conditions.
This way, you eliminate plant shock. On average, you’ll be planting the grass at the same depth as the roots in the host grass. This is usually about 3 inches wide, and 6 inches deep.
Spacing
Space each plant about 3 inches apart if you want that full coverage appearance.
If you want them to grow larger, space them at least 6-8 inches from each other. This will give them more space to grow. If you plant them too close together, you have two options:
- Provide ample nutrients in the soil
- Thin to the strongest plant
Use the 4” depth ring to harvest plugs for dwarf varieties. Space plugs 3” apart. You can separate clumps into sections each with several stolons and plant up 1 foot depending on how packed you want it to be.
Watering
Water your mondo grass at least once per week. Adjust as necessary for rain or drought. They can withstand some degree of drought, but need water in order to maintain their beauty.
1-2 inches of water per week is sufficient for most gardens. The soil should remain moist between watering sessions. Don’t let it dry out. But don’t overdo it either. Overwatering mondo grass will lead to fungus or create a breeding zone for pathogens. So don’t do it!
Some people water when the top inch of the substrate is dry. This is acceptable if you want to reduce the risk of fungal issues. But use a moisture meter to monitor it so it doesn’t go completely dry on you.
When the plant becomes established, it can tolerate much drier conditions. Mondos prefer slightly moist soil but can tolerate dryness when they have developed roots. They will slow their growth if dry.
Mulching
Mondo grass will appreciate some light mulching around the top 1-2 inches of the soil line. You can put leaf litter, leaf mold, or straw mulch.
This will help retain water and reduce your need to constantly keep it moist. It also helps keep weeds down. Use organic mulch if possible.
Plant food
Supplement with organic matter such as compost or slow-release granular fertilizer in the spring. This will help increase their nutrient availability during the active growing season.
Use NPK ratios of 10-10-10. General purpose, slow release fertilizer is key. You can find this in your local garden center for cheap.
If your substrate has a bunch of nutrients in it, then you don’t really need plant food. Remember that compost, manure, leaf litter, mulch, bone meal, etc. are fertilizers themselves.
Overdoing it can bring in insects because your mondo won’t use it all up.
So the bugs will eat it instead. Use granulated plant food in the early spring before your mondo grass actively grows. A balanced plate of food with a 10-10-10 NPK ratio is good enough.
If you want to get fancy, use a fertilizer with higher nitrogen and potash (the N and K values in NPK) that are specifically formulated for grasses or shrubs.
This will replenish necessary nutrients so they can consume them for the season.
Sunlight
These plants will grow in full sun, but partial sun is ideal. Filtered or dappled sunlight cast over the mondo grasses not only looks amazing, but it’s optimal for their growth.
They thrive in areas with filtered light, so plant them next to taller foliage or behind artificial structures. Sunlight that stems from the early morning is preferred over the scorching sun in the noontime. If you compare shaded mondos vs. full sun mondos, the shaded ones have that nice dark green coloring.
Full sun mondos are generally lighter in color. But this varies on multiple variables like the type of mondo plant, watering regime, pH, plant food, soil quality, location, etc.
Temperature
Mondo grass is hardy down to -10F when fully established. Of course, this will stop its growth completely.
It prefers warmer temperatures between 60-70F. It’s a cool sun plant. If you’re in the desert with hot and arid conditions, increase your watering regimen or plant in shady plots.
The grass is robust, hardy, and will handle most climate conditions. It just needs water with filtered light. Even in extreme temperature dips, it can be tolerant to frost.
So there’s no need to worry about small dips. It’s also heat tolerant as well. It can tolerate 90F or higher with ease if water is supplemented. Some light spritzing may be necessary to increase humidity in warmer climates.
Humidity
In dry regions, water more often or spry the foliage with water to increase humidity around it.
If the leaves turn brown or dry, increase watering. Monkey grass thrives in humid environments, so you need to keep it moist so the humidity remains elevated for it to grow.
Use humus-rich moisture-retaining substrate to help keep humidity high. If you’re in the southeast US, humidity is naturally high. This is ideal for mondo grass!
Environment
Mondo grass prefers slightly acidic soils with plenty of rich, organic materials to feed on. Ophiopogon japonicus is more of a lily-like plant than true grass.
In some parts of the southeastern US, O. japo