Ophiopogan planiscapus ‘Nigrescens’

Black Mondo Grass

Ophiopogan planiscapus ‘Nigrescens’

Also known as ‘Monkey Grass’ as well as ‘Black Mondo Grass’ , you could get a little confused as a few other grasses are called ‘Monkey Grass’ so lets stick with the botanical name Ophiopogan planiscapus ‘Nigrescens’.

This is one of the most sought after low growing ornamental grasses, and with good reasons. It is easy to grow, low maintenance, spreads slowly to form a good clump and it also looks great.

Although it does have pink flowers in summer it is really the year round foliage that is the main attraction.

Plants are available as small bare rooted rhizomes by mail order, they are also available as larger more established plants in containers. The small bare rooted rhizomes are the cheapest way to plant out a larger area.


Generally regarded as hardy in USDA zones 7 – 10. So no really heavy freezes and no tropical conditions either. In colder zones it van be lightly mulched in winter and it may survive.

Often said to be slow growing, however this is only true in poor soils and cold climates. Given warmth and moisture it will happily send out runners after 12 months, these appear as new shoots around 6 inches from where it was originally planted. We would not say it is a vigorous grass, but certainly not slow for us.

Used in landscaping as a grass alternative for low traffic areas, as feature in Japanese style gardens, for underplanting small shrubs in containers as well as for a border to paths.


  • Full sun to light shade
  • Best planted in early spring
  • Water in well with a liquid seaweed fertiliser to aid root development.
  • Plant container plants at around 6 inches apart (depending on size) to form a dense clump in around 3 years.
  • Bare rooted rhizomes (individual plants or plantlets) are best planted at around 3 inches apart.
  • Humus rich well drained soil
  • Mulch around clumps to help retain moisture. Use an organic mulch in garden situations, this will break down to improve soil structure.
  • Fertilizer with a slow release type in spring
  • Some gardeners like to cut the old foliage back in spring, some even use a mower on established clumps.


  • In damp areas slugs and snails can be a problem.
  • In areas with poor drainage root rot can be an issue.
  • In deep shape Black Mondo Grass may not flower.
  • In deep shade growth will not be strong, a minimum of good filtered light is required for strong healthy growth.


  • Ophiopogan planiscapus – Green foliage
  • Ophiopogan planiscapus – ‘Arabicus’


Ophiopogan planiscapus ‘Nigrescens’ Propagation from runners
Easy by division of established clumps in spring.

The plantlets in the clump send out rhizomes or runners and these form the new plants. The runners can come up close to the plant or around 6 inches away depending on the conditions. ( see picture right)

  • Lift the clump with a garden fork.
  • Divide individual plants
  • Trim the foliage by 1/2
  • Replant the very small plants into containers and grow on in a container until reestablished. Water in with a liquid seaweed fertiliser.
  • Mulching around clumps with a good organic mulch seems to encourage the clump to spread more rapidly.

Propagation from seeds is also possible, however some of the new plants will revert to the green form.

  • Ripe seeds are essential, so allow the seed pod to begin to open before collecting.
  • The dark outer casing needs to be removed.
  • Use a tray with individual cells for ease of transplanting later on.
  • Plant seeds around 1/2 inch deep.
  • Keep moist and provide some bottom heat for faster germination.
  • From seed to planting out may take 4 years.


  • Excellent low maintenance ground cover for low traffic areas.
  • Humus rich well drained soil.
  • Full sun to light shade.
  • Dark foliage and lilac to pink flowers in summer
  • Grows well in containers.