Shiny, blackish blades form a low upright mound, lifted in midsummer and late summer by delicate pinkish-white flowers. Black mondo grass (Ophiopogon planiscapus ‘Nigrescens’) is a go-to for edging beds and rock gardens, where the dark leafage makes contrast easy; give it rich, well-draining soil with plenty of humus and it thrives.
| Botanical name | Ophiopogon planiscapsus ‘Nigrescens’ |
|---|---|
| Common name | Black Mondo grass or black lilyturf |
| Family | Liliaceae (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 (no limestone) |
| Flowering | midsummer to late summer |
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).
Planting dates can be any time in early spring or mid-spring. However, ideal timing is, as always, fall.
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 your Ophiopogon is very simple:
When properly planted, O. planiscapsus “Nigrescens” isn’t particularly vulnerable to disease.
Pests are another matter. Young leaves are certainly a favorite of slugs.
In pots, suspect vine weevil grubs if a clump loosens and pulls up easily; tip it out and check the compost around the roots.
‘Nigrescens’ is the famous black one, but the genus offers greener and variegated forms for ground cover and edging. Here are the ones you are most likely to find on sale.
| Variety | Leaf colour | Height | Best use |
|---|---|---|---|
| ‘Kyoto Dwarf’ | Dark green | 2 to 4 in (5–10 cm) | Lawn substitute, tight low carpet |
| ‘Nana’ | Deep green | About 4 in (10 cm) | Between paving slabs and stepping stones |
| ‘Ebony Knight’ | Black-purple | 6 to 10 in (15–25 cm) | Dark accents in beds and containers |
| ‘Nigrescens’ | Near-black, glossy | 6 to 10 in (15–25 cm) | Edging and contrast planting |
| ‘Gyoku-ryu’ | Dark green | 1 to 2 in (3–5 cm) | Troughs, bonsai underplanting, crevices |
Ophiopogon is excellent in flower beds and in rock garden. 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. Sounds crazy, but this black grass is also perfect for white gardens!
Add a few mineral ornaments or mineral mulch to the growing bed around your Ophiopogon planiscapsus. The black color highlights the harsh, pure touch of rock and gravel.
