How to Plant, Grow, and Care for Ophiopogon Japonicus

If you’re looking for a grass-like, care-free ground cover that will add texture to your landscape, then look no further than this popular evergreen grass, Ophiopogon japonicus, commonly known as mondo grass. Mondo grass originated in Japan and China and is known as the traditional ground cover of many Japanese gardens.

This ornamental grass is very similar to black mondo grass, and in fact, it’s a direct relative. While black mondo grass is dark and spooky-looking, the dwarf lilyturf, or just mondo grass, is a lovely light green hue and looks great as an accent ground cover.

Technically not a grass at all (it’s more closely related to the lily than to most grass species), it’s a lovely species that’s able to handle things that most plants can’t stand – like growing under black walnut trees as it’s juglone-resistant. It can also handle deeply shaded areas, is resistant to salt, and is deer- and rabbit-resistant.

A popular evergreen species, it can also take full sun conditions and will produce white to lilac flowers if it’s happy enough. These flowers are tiny, but they form in clusters along the side of the leaves and their bloom stands out from the narrow-bladed leaves. These flowers may even bear fruit which will form as a tiny, bright blue berry at the base of the foliage. 

Overview

Plant Type Ornamental grass, lilyturf Family Asparagaceae Genus Ophiopogon Species Ophiopogon japonicus	Native Area China, Japan, Korea Exposure Full sun to partial shade Height 6-15”, dwarf varieties 3-4” Watering Requirements Regular	Pests & Diseases Slugs, snails, fungal issues, root rot Maintenance Moderate Soil Type Well-draining Hardiness Zone 6-10

What is Ophiopogon Japonicus?

There are two types of Ophiopogon japonicus: a standard type and a dwarf type. The standard type very easily spreads via stolons, which is an above-ground runner. This makes it an excellent choice for a large area that you wish to cover like a shady area where traditional turf grasses don’t grow as well.

The dwarf type does not spread this way and grows in dense tufts. This makes it easier to control and better suited for borders or filling in spaces between pavers in the garden.

Native Area

As mentioned above this grass-like evergreen originated in Japan and China and is known by many common names such as mondo grass, dwarf lilyturf, dwarf mondo grass, Japanese lilyturf, snake’s beard, and monkey grass. 

Characteristics

Mondo grass can be identified by its attractive evergreen foliage which appears as dark green-blue strap-shaped leaves. The flowers are small with six petals and the flower color ranges from white to pale lilac flowers. It will generally bloom in early summer. This ground cover is an evergreen that will remain green and grow year-round though its growth may slow in the winter. This makes an excellent low-maintenance border plant as it can survive anywhere from full sun to shady areas.

It does produce small cobalt blue berries that are not toxic. However, there are no known culinary uses for them. The berries look like blue versions of asparagus berries, which makes sense because this plant is in the Asparagaceae family, which is the same family of plants as common asparagus.

How to Grow

Mondo grass is low to medium maintenance and with the following requirements met, you will enjoy its evergreen strap leaves adding texture to your landscape through summer and winter. Most of the time, you’ll even find it to be care-free.

Light

Mondo grass can tolerate full sun to full shade, although the best site for this grass may be partial shade. In sunny areas, the foliage will fade to a lighter green, while moving this plant to shady areas will bring out the dark green leaves.

Water

As with most plants grown in warmer climates, the ideal time of day to water is in the morning so that the moisture has a chance to soak into the soil before the heat of the day can evaporate it. However, if you’ve missed this window of opportunity then the second-best option is to water it in the evening.

Take care to avoid wetting the foliage as this may cause fungal issues. Because of their small size and low growth profile, it is easiest to water this plant with a drip irrigation system. Once established, these plants are drought-tolerant and will survive the heat without much attention. It’s better to underwater rather than overwater these plants as they are also susceptible to root rot. In the winter, as their growth slows, reduce the amount of moisture. 

Soil

This traditional ground cover can survive in a multitude of soil types and can even be grown hydroponically. This makes it a great option for a border around a pond as well. It has also been spotted at big box pet stores being sold as an underwater aquatic plant, but that is not advisable for this plant. It will survive completely submerged for a few weeks and then eventually die as its not an aquatic. This plant prefers slightly acidic to neutral soil with a pH of 5.5-7.

It can be grown in containers as well as long as they are filled with well-draining soil. It does particularly well on slopes as water drains away from the roots.

Temperature

Ophiopogon japonicus is sensitive to frost. A light frost may cause damage that it can recover from, but a hard frost will severely set your plants back. For this reason, growing this plant in USDA hardiness zone 6-10 will ensure its survival. 

Fertilizing

Another aspect that makes mondo grass low maintenance is the fact that it doesn’t require any fertilizing at all. If you wish to give it a boost, then a top dressing of compost in early spring will be sufficient. Otherwise, it survives just fine in many soil types and situations as long as the soil is well-draining. 

Maintenance

Pruning is not necessary for this plant. It will grow until it reaches its mature height and then focus on roots, flower production, and spread. Unlike traditional turf grasses, it does not need to be mowed and can tolerate light foot traffic. You’ll only ever need to remove dead or damaged foliage. 

Propagation

It is easiest to propagate Ophiopogon japonicus by division. In early spring dig up a clump of mondo grass and tease apart the roots until you have several sections. Replant each section with at least four-inch spacing and they will eventually spread to fill in the gaps.

Mondo grass can also be grown from seed, but this plant is very slow growing so it will take a while to get a viable transplant when growing from seed. 

Common Problems

As mentioned, mondo grass is very low maintenance, shade-loving, evergreen, deer-resistant, and a perfect border plant. There aren’t many pest and disease issues with this plant, but there are a few things for which to keep an eye out. 

Growing Problems

Heat can be an issue for these lily turfs, particularly reflected heat from walls, walkways, and the like. Urban gardening can be filled with pitfalls of this sort in and around garden beds or containers. As a result, it’s recommended during the summer months to provide a partially shaded location away from hard scapes that can absorb and radiate heat from the sun. Keeping the soil moist during hot weather can also help your plants handle a bit more heat. Shade cloth arching over beds may also help reduce warmth in gardens where these are planted.

Pests

Mondo grass is rabbit and deer-resistant. However, slugs and snails have been known to munch on the leaves from time to time. If you see holes in the leaves and they appear to wilt, then this may be an indicator that slugs or snails are present. Visually inspect the leaves. If you have chickens, this is an opportunity to set them loose on your mondo grass for some tasty treats. For those of us without a backyard flock, the best course of action is a slug and snail bait. There are organic baits made from iron phosphate that are safe to use around wildlife, people, and pets. 

Diseases

Fungal diseases like anthracnose can affect these shade-loving ground covers. This is a fungal disease that usually appears during the cold and wet early spring in areas with high humidity. It causes leaf spots, cupping, or curling of the leaves and leaf drop. The best preventative measure would be to ensure there is good air circulation around your plants. After a lilyturf is severely infected it’s best to remove and destroy it to keep the fungal infection from spreading to other lilyturfs. Mild infections can be treated with a copper fungicide.

Mondo grass is susceptible to root rot caused by pythium fungal strains that develop in overly-moist conditions. Since this plant is rather drought-tolerant, it’s better to underwater it than overwater it and risk root rot issues. Root rot is hard to reverse if it has already progressed too far. If the plant appears brown and mushy at the base then this may be a sign of it developing. Back off on watering and let at least the top inch of soil around the roots dry out completely before watering again. 

Frequently Asked Questions