Black bog-rush
Schoenus nigricans · Cyperaceae
The gardener's calendar
Ideal time to plant black bog-rush: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Family
- Cyperaceae (Cottongrasses and sedges)
- Foliage
- Evergreen, fine and filamentous, grey-green to blackish-brown
- Flowering
- May to July, very discreet blackish-brown spikelets
- Adult size
- 30 to 60 cm tall, compact and tufted habit
- Growth
- Slow to moderate
- Hardiness
- Zone 5 to 10 (very hardy, tolerates -15°C)
- Origin
- Europe, North Africa, Mediterranean basin
- Soil type
- Well-drained, tolerates poor soils and seasonal moisture
Care
Sunlight
Plant blackish sedge in full sun to optimize its coloration and habit. It tolerates partial shade but will lose elegance and its characteristic tint. It's a hardy plant that appreciates open, airy locations.
Soil
This Cyperaceae prefers light, well-drained soil, even poor or sandy. It exceptionally tolerates wet winter soils and dry summer soils, ideal for rock gardens or peaty areas. Improve drainage if your soil is very heavy.
Watering
Once established, blackish sedge is very frugal. Water moderately during establishment and prolonged dry spells. In normal climate, rainwater is more than sufficient. Avoid excessive moisture in pots or stagnant areas.
Fertilizing
No fertilizer is generally necessary. This plant thrives in poor soils. Fine compost on the surface in spring every 2-3 years is enough if the soil is very depleted. Prioritize drainage quality over fertility.
Pruning and cleaning
Perform light cleanup in late winter or early spring to remove dried leaves and dead foliage. Gently comb the tuft with a leaf comb or by hand to avoid damaging the evergreen foliage. No radical pruning needed.
Diseases and problems
Blackish sedge is very robust and rarely diseased. Excessive winter moisture can promote root rot in poorly drained heavy soils. If problems arise, improve aeration and drainage. No major pests known under normal conditions.
Did you know?
Blackish sedge is a true landscape chameleon: its foliage shifts from grey-green to deep blackish-brown depending on the season and sun exposure, creating subtle shadow and light effects in rock gardens. Its scientific name 'nigricans' literally means 'darkening.' In its natural Mediterranean and Atlantic environment, it colonizes seasonally wet areas and alkaline marshes, where it plays an important ecological role for specialized flora.
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.
Add this plant to my garden →Plants from the same family
- Blue sedgeCarex panicea
- Spring sedgeCarex caryophyllea
- Pendulous sedgeCarex pendula
- Bird's-foot SedgeCarex ornithopoda
- Gray's sedgeCarex grayi
- Strict sedgeCarex stricta
Tips generated and checked by Viridia — adapt them to your local climate.