Does it really stay black?

Yes, the leaves maintain their dark purple to black color throughout the year.

How fast does it spread?

It is a slow grower and will not quickly take over your garden beds.

Plant guide

Black Mondo Grass.

Ophiopogon planiscapus 'Nigrescens'

Pronounced oh-fee-oh-POH-gon plan-ih-SKAY-pus

Also known as Ophiopogon planiscapus 'Nigrescens', Black mondo grass, Mondo grass, black mondo

This striking plant is a favorite for adding dark, dramatic color to your garden. It is a slow growing, grass like perennial that forms dense clumps of arching foliage. You will love how its deep purple to black leaves contrast with lighter plants.

At a glance

Care level: Easy
Plant type: Perennial
Light: Partial shade to full sun
Indoor light: Bright indirect
Water: Every 5 to 7 days
Mature size: 6 to 12 inches
Growth rate: Slow
Hardiness: USDA 6 to 10
Bloom time: Mid to late summer

Care

Keep the soil consistently moist but never soggy to prevent root rot. Watch for browning leaf tips, which often signal that the soil has dried out too much. It thrives best when given a bit of protection from the harshest afternoon sun.

Watering: Water when the top inch of soil feels dry to the touch.
Feeding: Apply a balanced liquid fertilizer during the active growing season.
Pruning: Trim back any damaged or dead foliage in early spring to encourage fresh growth.
Repotting: Repot only when the plant becomes root bound or you want to divide the clumps.
Soil: Humus rich, well draining soil
Soil pH: 6.0 to 7.0
Temperature: -15 to 35°C
Humidity: 40 to 70%
Drought tolerance: Moderate
Lifespan: Perennial, typically 10 plus years
Deer and rabbits: High

Signs it needs repotting

Roots growing out of the drainage holes
Water sitting on the surface for too long
Growth slowing significantly

Safety

People: The plant is generally considered non-toxic, but ingestion is not recommended.
Pets: This plant is generally considered non toxic to cats and dogs.
Children: The small berries may pose a choking hazard to small children if ingested.
Contact allergens: There are no known significant skin irritants associated with this plant.
Airborne allergens: It does not produce significant airborne allergens.
Edibility: This plant is not intended for human consumption.

How to identify it

Arching, grass like foliage
Deep purple to black leaf color
Small bell shaped pale flowers
Dark blue to black berries
Forms dense, spreading clumps

Height: 0.15 to 0.3m
Spread: 0.2 to 0.4m
Leaves: black, dark purple, evergreen
Flowers: white, pale lilac, 0.5 to 1cm
Fruit: black, Autumn

Problems to watch for

Slugs and snails · These pests may feed on the foliage, especially in damp conditions.

By symptom

Plant problems by symptom

Check your black mondo grass from a photo

Pocket Botanist looks at a photo of your plant and tells you what's wrong and what to try first.

Growing it

Propagation: division
When to plant: spring, autumn
Overwintering: In colder regions, apply a layer of mulch around the base to protect the roots from extreme frost cycles.
In containers: It grows well in containers, provided the pot has excellent drainage and is at least 20 centimeters wide.

Division

Dig up a mature clump in early spring.
Gently pull or cut the clump into smaller sections with healthy roots.
Replant the divisions immediately at the same depth as the original plant.

Pair this plant with light colored foliage to make the black color stand out.

Grows well with

Japanese Maple · The delicate foliage of the maple contrasts beautifully with the dark grass.
Hosta · Hostas provide a bright color contrast against the dark mondo grass.

Similar species

Mondo Grass · This is the standard green version of the same genus.

Science

Family: Asparagaceae
Genus: Ophiopogon
Order: Asparagales
Class: Liliopsida
Native range: Japan
Conservation: This plant is not currently of conservation concern.

It thrives in the dappled shade of forest floors where it competes for moisture in well drained soil.

Value to wildlife: nectar source
Pollinators: bees
Uses: groundcover, container plant, border edging, rock garden

Through the year

JFMAMJJASOND

Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 5/9
Light: 4/9
Temperature: 5/9
Moisture: 5/9
Nutrients: 4/9

Taxonomy resolved against GBIF.

Questions people ask

Does it really stay black?: Yes, the leaves maintain their dark purple to black color throughout the year.
How fast does it spread?: It is a slow grower and will not quickly take over your garden beds.

Where the name comes from

The name Ophiopogon comes from the Greek words for snake and beard, referring to the leaf shape and flower clusters.

Good to know

It is commonly known as black mondo grass.
The dark color is caused by high levels of anthocyanins.
It grows slowly compared to standard green mondo grass.

Also in

Deer-resistant plants

Keep your black mondo grass growing

This page is a general guide. Save your plant in Pocket Botanist and you get care reminders timed for this plant, plus a care history that shows what worked.

Get the app

This guide was generated with AI on October 24, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.