How to Grow Mondo Grass (Monkey Grass) – Beginner’s Care Guide

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, .)

Quick care guide: Mondo grass

Plant typePerennial grass
OriginSoutheast Asia
Scientific nameOphiopogon japonicus
Other namesLilyturf, monkey grass, black mondo grass.
Soil typeOrganic, rich, loamy, peaty, sandy, clay, loose
Soil pH5.5-6.5 (slightly acidic)
Sunlight requirementPartial sun, full sun (for lighter coloration)
Bloom seasonSummer
ColorsDark green, lime green, purple, variegated, blue, yellow, white, red, black
Max height16 inches
Max width14 inches
Low temperature tolerance-10F
High temperature tolerance90F
Ideal temperature range60-70F
HumidityModerate (50% or higher), spritz with water if needed to bump it
Watering requirements1-2 inches per week, adjust for rain or drought, established grasses require less water
Fertilizer requirementsBalanced, slow release granule plant food in early spring before growing season
Plant food NPK10-10-10
Days until germination14-180 days
Days until harvestNot harvestable, seeds can be collected from the fruit
Bloom timeMarch, April, May, June, July
Speed of growthVery slow
Hardiness zonesUSDA hardiness zones 3-10
Plant depthFrom 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 spacing12-18 inches for large varieties;
3-5 inches for dwarf grasses
Plant withImpatiens
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 withPlants that have opposing care requirements
Propagation methodFrom seed, dividing root balls, seedling transplants
Common pestsSnails, slugs
Common diseasesPythium root rot, leaf spot, blight
Indoor plantNo
Outdoor plantYes
Grown in containerYes
Flowering plantYes
Beginner friendlyYes
Care levelMinimal to none (Easy to care for once you get the hang of it, good for beginners)
Best usesPathing, 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

Some berries growing on mondo grass.
These berry fruits are growing from mondo grass, but they’re not edible! (By Alpsdake – Own work, CC BY-SA 4.0.)

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

Mondo grass in garden.
Does this look more familiar to you? Mondo grass is often used for filling gaps like this. (By By Forest & Kim Starr, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=6151223, CC BY 3.0)

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. japonicus will thrive natively. But for other western states, it needs to be introduced.

In the wild, you can find mondo grass growing in dappled sunlight. They can be found next to roads in rural areas. It’s also found along border paths, between stepping stones, flower beds, lawns, or as plant cover.

It has a tendency to bunch together so it’s often found on forested slopes. They don’t like excess water and full sun. Mondo grass comes from Southeast Asia.

Pruning

Mondo grass plants.
These grasses are ready to be planted. (By Forest & Kim Starr, CC BY 3.0)

You’ll need to prune your mondo grass using sharp, clean, sterilized shears a few times during the season. These grasses may turn brown or black in cooler regions.

By the time the cool season rolls in, the grass can appear to be ragged, torn, or wilted due to the changing season. Use a pair of shears to gently cut back the spent flowers, dead leaves, or wilting foliage. Shaggy or unfavorable leaves should be removed in the winter.

Cut your mondo grass back by 30% of its size. This will help encourage new foliage to grow. They benefit from reseeded mulch or compost early in the season to help increase their nutrient profile.

Larger mondo grasses can be divided every 2-3 years. Smaller container plants can be divided when they root. Don’t divide too early or else the new plants will have a difficult time developing their root systems.

Overwintering

Monkey grass needs basic pruning for the winter. Pull out leaves or tufts of foliage that turn yellow or brown in the winter.

If you’re in zones 5-10, nothing needs to be done other than the removal of spent flowers or willing grass. The grass will start to fade to black as the seasons approach winter.

Depending on the species, some will last through winter without issues. Others will change color or wilt. Regardless, you likely don’t have to do anything if temperates don’t dip too much during the cold.

Stop or reduce watering in the winter. Reduce it down to 25% of the regular amount and see how your grass reacts. Little needs to be done in the wintertime other than checking for insects.

Mondo grass is evergreen in warmer climates. It’ll stop growing in the winter if temperatures drop below -5F. But will resume in the spring.

If temperatures dip, supplement with mulch to protect the roots from the cold. It helps insulate the root ball.

Do not feed fertilizer in the wintertime. The plant may not “drink” it and this will bring in bugs.

Companion plants

There are countless plants that pair well with mondo grass. Some compatible companion plants include the following:

  • 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

It looks good next to light-colored foliage. Silver or gold foliage really brings out the colors of mondo grass. Plant next to similar-sized plants.

Don’t plant with

You should avoid planting mondo grass with plants that can outcompete nutrients. This grass can be quite greedy with the free nutrients in the soil column.

If planted near other plants that are poor growers, it can choke out other plants. If you don’t provide enough distance between mondos and other plants (including other mondos), they’ll compete for nutrients. Provide at least 12 inches from other plants.

Pests

These grasses have minimal problems. Mondo grass is robust, tough, versatile, and has very few issues once established from pests.

Some insects you may have issues with include slugs, snails, and other gastropods. When it’s warm outside, these will show up on your monkey grass.

They love feeding on the foliage because it’s so easy to reach and tender. This makes it easy to digest for them. But serious damage from bugs isn’t likely. You’ll spot wilted foliage, holes in the grass leaves, or changing colors.

You can remove these by hand and dip them into a bucket of soapy water. Beer traps, diatomaceous earth, or copper tape can be useful as DIY techniques to keep bugs off your monkey grass.

Diseases

There are a few problems your grass can encounter. Some of them include pythium root rot and leaf rot, both caused by excess water in the soil.

Dwarf varieties are vulnerable because they’re so close to the soil line. Prevent these issues by watering less and reducing humidity. Proper spacing, pruning, and not over-watering will help prevent monkey grass problems.

Usage scenarios

Monkey grass is a low creeping tough evergreen grass that’s commonly used as a plant cover. It’s even used as a lawn in some driveways.

This low-maintenance grass is perfect for shady areas to fill in for gaps, voids, or cracks. Use as plant material between pathing, borders, fencing, etc.

The uniform growth with neat, clean foliage is perfect for containers or edgings. It can also be used for knot gardens or geometric plant beds.

Some people grow them in gravel, rock, clay, or zen gardens. They’re tolerant to deer, most wildlife, pests, and even drought. Mondos also have some degree of tolerance to salinity, which makes them good for coaster gardens, marshes, streams, ponds, or other water features. Or you can just grow it for the beauty of the fruits!

Commonly asked questions

This section covers some commonly asked questions about mondo grass care from readers. You may find it useful for your purposes.

If you don’t find an answer to your question, please post it in the comments section!

Why is my mondo grass turning brown/yellow?

This is usually due to too much sun, too much water, or the general care requirements are not being met.

Perhaps this video explains it vast detail:

Is mondo grass annual or perennial?

Mondo grass is a perennial ornamental grass. If grown within the right zone, you should have no problem getting it to overwinter.

This grass will come back on its own next spring. That’s the beauty of perennials. You can enjoy the fruits of your labor season after season.

When your mondo grass gets really big, you can enjoy those arching leaves of green!

How long does it take for mondo grass to grow?

That’s a tough one. Germination from seed can take up to half a year to successfully sprout.

It can also take as little as 2 weeks. As you can see, it greatly varies depending on where you’re located, the mondo species, and how you grow it.

From division, you can expect results much quicker. Standard mondo grass will establish itself within 1-2 years.

You know it’s done when it’s about 12 inches wide. Dwarf grasses will take almost twice as long to reach their max width.

Can I walk on mondo grass?

Mondo grass can tolerate being walked on, but not on a daily basis. Avoid stepping on it if possible. Foot traffic will destroy it over time.

Place small stepping stones or some other pathing to avoid stepping on it. Use dwarf mondo grass only for high traffic areas as it’s more tolerant of being walked on.

Do NOT use regular mondo grasses for traversing.

Does mondo grass need a lot of water?

Mondo grass should be watered thoroughly and deeply until they’re established. Water 2-3 times per week to help them develop strong root systems.

Eventually, they only need to be watered once per week. They become drought tolerant over time, to which you can reduce watering to just an inch or so per week. Keep the soil moist, but not wet.

Can dogs eat mondo grass?

Monkey grass is harmless to dogs in small quantities. Dogs may chew on it occasionally without issues.

If they consume too much of it or are sensitive (or have other issues), it can cause stomach or digestion issues. Mondo grass is not listed on the ASPCA list of poisonous plants. You should avoid letting your dog consume mondo grass in large quantities, but smaller chomps here and there should be OK for normal dogs that don’t have sensitivities.

How do you keep weeds out of mondo grass?

Regular mulching will help keep weeds out of plant beds. Mulch suppresses weeds, but helps retain moisture for your plant to drink over time.

Use a high-grade mulch to help keep weeds out of mondo grass or else they’ll compete for nutrients and your grasses will get jumbled. Oh, and pull the weeds as you spot them!

What is the difference between mondo grass and dwarf mondo grass?

There’s a lot of confusion between the regular mondo and dwarf mondo.

It’s simple: dwarf mondo is just a smaller, compact version as the name implies. Dwarf mondos have slimmer leaves that give a petite build.

Regular mondo grows up to 12 inches, but the dwarf is about half that size. It only reaches about 3-6 inches tall. The care between the plants is similar.

They also look almost the same. Dwarf mondo is darker in color and is more cropped.

Will dwarf mondo grass grow in full sun?

Yes, dwarf mondo grass will grow in direct sun. But you’ll likely end up with more lime green foliage over dark green.

Use dappled light when possible. Filtered sunlight is ideal for that dark green foliage. Since people use dwarf mondo for lawns, sometimes it’s not possible to plant in shade.

That’s OK, but don’t expect the nice coloration that a filtered sunlight plant possesses.

Further reading/references

Enjoy your mondo grass!

Monkey grass in Japan.
Look at the monkey grass growing on the slopes of Japan.

You now know everything you need to know about how to grow and care for mondo grass. You’ll see that it’s so easy you wish it was earlier.

It’s pretty to look at. It’s an evergreen. And it blooms. Plant cover. Pathing. Bordering. Or void fill. It’s all up to you. Mondo grass is versatile and suits a variety of purposes.

Do you have any questions about growing mondo grass? Post them in the comments section and ask! Thanks for reading!

Leave a Comment

Your email address will not be published.