How To Care For Black Mondo Grass

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Ophiopogon planiscapus [Of-eyo-poe-gon, Plan-iss-kap-us] belongs to the Asparagaceae family of flowering plants. 

It is small and evergreen with tufts of leaves resembling grass. 

Up Close Black Mondo Grass (Ophiopogon Planiscapus)Pin

The black mondo grass is native to Japan and some other Asian regions where it may grow on its own or on forested slopes. 

Black mondo has been given the Award of Garden Merit by the Royal Horticultural Society. The plant earned its common name from its black foliage color.

Other common names include:

  • Mondo grass black
  • Monkey grass
  • Black lilyturf
  • Black Dragon
  • Ebony Night
  • Arabicus
  • Little Tabby
  • Silver ribbon

Named cultivars of the plant include:

  • Ophiopogon planiscapus ‘Nigrescens’
  • Ophiopogon planiscapus ‘Black Dragon’
  • Ophiopogon planiscapus ‘Nigra’
  • Ophiopogon ‘Black Dragon’ 

Learn more about Ophiopogon:

Black Mondo Grass Care

Size & Growth

The ophiopogon consists of grass-like leaves which may grow to a height of 6″ – 8” inches and spread over an area of 9″ – 12” inches. 

The black leaves start arching as they grow and resemble jet black straps.  

Flowering and Fragrance

As the plant blossoms, the leaves turn from green to dark purple, almost black color. 

The flowers grow in racemes of white flowers, purplish (purple-black) and very pale lilac flower color. The stems are quite short. 

The warmer the weather, the darker the plant becomes.

For some of its cultivars, the plant produces dark lavender, bell-shaped flowers before blossoming into dark purple or black berries in the fall.

The main bloom time of the black mondo is from July to August.

Light & Temperature

Ophiopogon grows best in a combination of full sun exposure and part shade or partial shade. 

It requires full shade in very hot climates. 

It is in full bloom during the late summer months and it is evergreen so it retains its leaves all year round. 

Although it may survive in hot climates, the plant thrives in warm regions.

According to the USDA zone, the ophiopogon grows in a hardiness zone from 6-11.

Watering and Feeding

This plant type has frequent water needs, around once a week to maintain the moisture content of the soil.

The hotter the climate, the more water will be required. Just avoid making the soil soggy. Frequent watering encourages good flowering.

The plant doesn’t require much fertilizer, a single dressing of compost in the spring should be sufficient. 

Additionally, if the soil is not acidic, fertilizer may be added before planting to balance out the soil pH levels.

Soil & Transplanting

Black mondo thrives in humusy, rich, well-drained, medium-moisture soil. It prefers slightly acidic soil. 

It is quite a hardy plant and may survive in dry or salty soil. 

It may grow in a range of soils such as loam, clay or sand, although clay should be avoided since it makes it harder for the roots to penetrate through.

Grooming and Maintenance

The plant is quite low maintenance, but for a neat appearance as a ground cover, trim the old foliage before new leaves start growing. 

Don’t over-prune the black mondo since its growth rate is quite slow and may start looking bare if too much of it is cut.

How to Propagate Ophiopogon Planiscapus

Black mondo grass may be propagated by lifting and dividing the underground stolons (fibrous roots) of the plant in spring.

  • Start off by using a garden fork to pry clumps of the plant out from the ground.
  • Break up the clumps with your hands ensuring each broken clump has a few leaves on it. 
  • If the roots have become thick and intertwined, you may need a knife or sharp gardening tool to break up the clumps.
  • Remove any dried parts of the roots or any parts which may have been affected by disease.
  • Replant the clumps keeping a distance of at least 4” inches between each, if there is a delay, keep the cuttings moist to keep the plant cells alive.

Once the cuttings have been planted in the soil, their maintenance and watering habits will be the same.

Ophiopogon Planiscapus Pest or Disease Problems

This hardy plant doesn’t have too many diseases or pest problems. It is both rabbit and deer resistant. 

The main thing to watch out for with this back mondo grass is slugs, snails and root rot.

These problems may be averted by not overwatering the plant and using slug repellant on the leaves.

Is Ophiopogon Toxic Or Poisonous?

The USDA has declared the ophiopogon to be non-toxic for both humans and animals. 

Despite this, there have been reported cases of people’s pets being poisoned by this plant.

Is Back Mondo Invasive?

Black mondo has invasive properties and may damage other plant species around it if the weather is extremely conducive to its growth. But, aggressive growth is unusual.

Suggested Black Mondo Grass Uses 

The ophiopogon has landscaping uses and is used as ornamental grass, as edging on a ledge and in rock gardens. 

It may be grown in containers on your patio for aesthetic appeal. 

It also provides a decent amount of ground cover and is a great companion plant with Liriope.

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