Black mondo grass
Ophiopogon planiscapus · Asparagaceae
📷 Didier Descouens · CC BY-SA 4.0
The gardener's calendar
Ideal time to plant black mondo grass: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Family
- Asparagaceae
- Foliage
- Evergreen
- Flowering
- Summer (July-August), inconspicuous white or pale pink flowers
- Adult size
- Approximately 30 cm tall
- Growth
- Slow to moderate
- Hardiness
- Down to -15 °C (zone 7)
- Origin
- Japan
- Soil type
- Well-drained, rich in organic matter
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Ophiopogon planiscapus covers shaded understory areas beautifully and makes an excellent groundcover; space the divisions 20 cm apart when planting. It needs no maintenance or fertilizer, even in poor soil.
The common mistake
Planting it in full sun or overwatering it: it yellows, gets leggy, and loses the dense, compact look that defines it.
The pro's trick
The 'Nigrescens' variety with its very dark foliage is the most dramatic in shaded areas: plant it thickly on light-colored mulched soil to maximize the contrast.
Seasonal watch
No remarkable seasonal concerns: it's practically indestructible.
Care
Light
Ophiopogon prefers partial shade to full shade, ideally under tree canopy or in partially shaded areas. It tolerates indirect sunlight but dislikes direct exposure to hot sun. This is a perfect plant for tricky corners of your garden that lack light.
Watering
Keep the soil regularly moist but not waterlogged, especially during spring and summer growth. Water moderately in winter and adjust frequency based on weather and soil type. In well-drained soil, weekly watering during dry periods is usually sufficient.
Soil
Plant your ophiopogon in soil rich in organic matter and well-drained to prevent root rot. Adding compost or potting soil at planting time improves structure and promotes establishment. Chalky soils are tolerated, though it prefers slightly acidic to neutral conditions.
Fertilizing
A balanced fertilizer application in spring (April-May) is usually enough to support seasonal growth. In very depleted soil, supplement with diluted organic liquid fertilizer once or twice during summer. Avoid excess feeding, which promotes overly vigorous growth at the expense of hardiness.
Pruning and maintenance
Ophiopogon requires virtually no pruning. Simply remove dead or damaged foliage in early spring to encourage vigor. This plant naturally produces runners that gradually expand the clump; let them spread or delimit the area you wish to cover.
Diseases and pests
This is a robust plant, rarely troubled by disease if not waterlogged. In overly wet soil, watch for root rot. A few slugs may damage young foliage in spring, but rarely severely. Good preventive drainage solves most problems.
Did you know?
Ophiopogon planiscapus is sometimes called 'serpent's beard' in reference to its fine, undulating foliage. Its dark blue or black fruits, rare in cultivation, are highly prized by birds in Japan, where the plant has been used for centuries as an ornamental ground cover in Buddhist gardens and traditional compositions.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
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Tips generated and checked by Viridia — adapt them to your local climate.