Ophiopohon planiscapus, incredible jet black grass

Black strands of grass with a few leaves

Ophiopogon planiscapsus ‘Nigrescens’ isn’t only original because of its shiny, long blackish leaves. It doubles its appeal with delicate pinkish-white flowers in summer.

Ophiopogon planiscapus, a few facts

Botanical nameOphiopogon planiscapsus ‘Nigrescens’
Common name – Black Mondo grass or black lilyturf
FamilyLiliaceae (lily family)
Type – rhizome perennial

Bearing – upright mound
Height – 6 to 10 inches (15 to 25 cm)
Planting density – 8 to 10 plants per sq. yard (m²)
Exposure – full sun to part sun
Soil – lots of humus, not chalky

Flowering – July-August

Planting black Ophiopogon

Black Ophiopogon planiscapus ‘Nigrescens’ is happiest in rich and well-draining soil.

That’s why, it’s important to add compost or soil mix to your soil upon planting if it’s too poor. Take note of how heavy it seems (clay soil). You may need to add sand to help excess water drain away.

Planting dates can be any time in March or April. However, ideal timing is, as always, fall.

Caring for O. planiscapsus ‘Nigrescens’

Blooming ophiopogon with soft violet flowers.Although it’s only a matter of minutes from time to time, your Ophiopogon planiscapsus ‘Nigrescens’ will require a bit of care if you wish to see it truly thrive. First advantage: once planted, you’ll never need to trim it. Nonetheless, you might want to remove old, battered leaves as winter gives way to spring.

In order to sustain high levels of humus, spread a little soil mix around the base of the plant.

You might reach a point where your Ophiopogon starts spreading a bit too far because of its rhizomes. If that’s the case, all you need to do is circle around the clump with a sharpened square spade. After that, simply remove what’s on the outside of the circle.

Ophiopogon is vulnerable to cold frost spells. If there’s a risk of exposure to intense cold, cover the clumps with either dead leaves or straw hay. Once the heap is ready, tether it down with a weighted net.

Propagating Ophiopogon ‘Nigrescens’

Propagating your Ophiopogon is very simple:

  • The only tool you’ll need is a spade or spade fork.
  • Pull the clump out, trying to protect the roots.
  • Split the clump into as many smaller clumps as you wish.
  • When finished, plant as recommended above.

Diseases on Ophiopogon planiscapsus ‘Nigrescens’

When properly planted, O. planiscapsus “Nigrescens” isn’t particularly vulnerable to disease.

Pests are another matter. Young leaves are certainly a favorite of slugs.

Landscaping and pairing

Ophiopogon is excellent in flower beds and in rock gardens. Thanks to its small size and color, it’s a definite go-to when marking out edges around your growing beds.
The dark hue of its leafage makes playing with contrast easy and fun, all the while granting your garden an original eye-catcher.

Great plants to pair with your Ophiopogon ‘Nigrescens’ are light-colored leaf perennials and grasses such as hosta, Carex hachijoensis ‘Evergold’, Achillea umbellata, Liriope muscari, etc.

Smart tip about Black Mondo grass

Add a few mineral ornaments or mineral mulch to the growing bed around your Ophiopogon planiscapsus. The black color keeps the harsh, pure touch of a rock garden.

Clump of Ophiopogon planiscapsus nigrescens bearing fruit, black leaves.


Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Ophiopogon grass blades by irpfander under © CC BY-NC 4.0
Blooming black Ophiopogon by Dan Fitzgerald under © CC BY-NC 4.0
Black ground cover with berry by J Brew under © CC BY-SA 2.0