Comprehensive Guide About Ophiopogon Planiscapus ‘Nigrescens’
Also known as: Black Mondo Grass, Black Lilyturf, Black Spider Grass, Monkey Grass)
Ophiopogon planiscapus ‘Nigrescens’ or, as more commonly known, black mondo grass, brings a dramatic purple-black – sometimes almost jet black – colour to the garden. It is a striking perennial with its dark foliage adding dramatic contrast to gardens. Set against green foliage, it adds depth and interest with its distinctive dark spidery leaves. It is native to East Asia.
Ophiopogon planiscapus ‘Nigrescens’ is also known as black spider grass, black lilyturf or monkey grass. Though not a true grass, it provides a dense carpet of elegant grass-like foliage that is evergreen, deer resistant and low maintenance. It has attractive small dark flowers that bloom in late summer and early autumn, followed by purple-black jewel-like berries. The black mondo grass is suitable as an edging plant, groundcover, container gardening and just about perfect for a section that needs dense low foliage with minimum care that is easy to control. Pair with bright plants (e.g., hostas or golden sedum) for contrast, or combine with ferns, heuchera, or white-flowering plants. Black mondo grass is not only popular for its dynamic colour contrast in a garden but for its easy care.
Black mondo grass is not toxic to pets, though berries may cause mild stomach upset.
By prioritizing drainage, light management, and minimal fertilization, you will enjoy the dramatic foliage of black mondo grass for years. The information below will help you plan where best to plant and how to grow and care for this ornamental perennial “grass” favourite.
Black Mondo Grass At A Glance
Type: Evergreen Perennial / Ornamental Grass
Location: Full Sun (cooler climates); Thrives in partial shade
When: Plant in spring or fall to avoid extreme temperatures
Seasonal Interest: Foliage Year-Round / Flowers Late Summer, Early Autumn / Berries Late Autumn, Early Winter
Size: 30 cm (12 in) Height, 20 cm (8 in) Spread
Cold Hardiness Zones: 5, 6, 7, 8, 9 (zone 5 will need winter protection)
Where to Plant and How to Grow Black Mondo Grass
Grow black mondo grass in moist but well-draining soil (sandy or loamy) in a sunny or partially shady site. Ideal conditions of morning sun and afternoon shade is prefect. It may tolerate full sun in cooler climates but will scorch in intense summer heat. Black mondo grass tolerates a range of pH levels but prefers slightly acidic to neutral (6.0–7.0). It can be planted in fall but best to plant in spring to give it time to establish itself before the winter.
When planting several new plants in one area, space about 15-30 cm (6-12 inches) apart, it spreads slowly via rhizomes. If planting in pots, ensure it has drainage holes and well-draining soil.
Black mondo grass annual care is minimum. If planted in a sunny location, ensure it is watered regularly during the hot months. Keep soil moist during establishment. It is a slow starter but once established, it gets dense and is more drought-tolerant in a partial shady location. Once mature, water when the top inch of soil dries out. Avoid overwatering to prevent root rot.
Trim dead or damaged leaves in early spring. Remove spent flower stalks unless seed propagation is desired.
Black mondo grass is not invasive nor a fast spreader. It is easy to divide the clumps. Offshoots can be detached easily and replanted. Ensure each division has roots. Replant immediately and water well. Divide clumps every 3–4 years in spring or fall to rejuvenate growth and prevent overcrowding.
The black mondo grass benefits from top-dressing with organic compost in spring. Use a balanced, slow-release fertilizer. Additional fertilizer is not needed during the year. Avoid excess nitrogen, which can dull leaf colour.
In zone 5, apply mulch for root protection. Potted plants should be moved indoors or moved to a sheltered location in harsh winters.
Pests, Diseases and Troubleshooting
The black mondo grass is generally pest and disease-free.
Slugs and snails may munch the young foliage. Apply organic bait.
Avoid soggy soil to prevent root rot, and ensure good air circulation to prevent fungal issues.
Pale leaves may indicate too much shade or over-fertilizing. Move to a sunnier spot or reduce feeding.
Slow growth is normal for this species; patience is key.
It is also deer resistant though rabbits may take a nibble.
RELATED TOPIC: Deer Resistant Plants And How To Keep Your Garden Deer Proof
