Scleranthus biflorus 'Lime Lava'

Lime Lava Cushion Bush

Botanical Name: Scleranthus biflorus 'Lime Lava'
Family: Caryophyllaceae
Origin: Australia/New Zealand; cultivar selection
Plant Type: Evergreen cushion-forming perennial groundcover

Overview

'Lime Lava' is a vivid lime-green selection of the cushion bush, forming dense, undulating mounds of fine moss-like foliage that ripple across the ground like molten green lava. The bright chartreuse tone lifts shaded and contemporary plantings, and its sculptural, self-shaping habit makes it a true conversation piece in rockeries and gravel gardens. As tough and low-care as the species, given the sharp drainage it demands.

Key Features

• Mature Size: 0.05–0.1 m H x 0.3–0.6 m W (spreading mound)
• Growth Rate: Slow; 5–10 cm spread per year; forming a firm, undulating cushion that knits together over time
• Foliage: Tiny, thread-like lime-green leaves in a dense, springy moss-like mat; brightest colour in good light
• Flowers: Tiny, inconspicuous greenish flowers in spring; grown entirely for foliage effect
• Seasonal Interest: Vivid lime cushion year-round; freshest in cooler months
• Wildlife Value: Low direct value; provides microhabitat for small invertebrates
• Tolerance: Frost hardy; moderate drought tolerance once established; wind-tolerant; will not tolerate waterlogging or humid, poorly drained sites
• Planting Density: Cushion/mass effect: 25–30 cm apart; feature spacing: 35–40 cm apart
• Pet Friendly: Non-toxic to cats and dogs; protect the cushion from heavy foot and pet traffic to keep its form

Where It Works Best

• Sunlight: Full sun to part shade; light afternoon shade keeps the lime tone fresh in hot SA summers
• Soil: Excellent drainage essential — sandy, gravelly or raised-bed soils; will not survive heavy or wet soils
• Water Needs: Establishment: light, frequent watering for 6–10 weeks. Established: deep soak every 2–3 weeks in summer; rarely in winter — avoid overhead watering and let the surface dry between waterings.
• Maintenance: Minimal — remove any weeds emerging through the cushion; no pruning or feeding required; avoid walking on it
• Lifespan: 10–20+ years; cushions improve with age
• Climate Zones: Best in cooler SA zones — Adelaide Hills and cooler metro; can struggle in hot, humid coastal summers
• Soil pH: Slightly acidic to neutral (pH 5.5–7.0)

Landscape & Design Ideas

• Bright living-sculpture feature in rockeries and alpine-style plantings
• Lime-toned textural contrast against dark foliage and stone
• Crevice and stepped-bed plantings between pavers

Why You Will Love It

'Lime Lava' brings electric chartreuse texture to the garden floor — a rolling, sculptural cushion that glows against rock and dark foliage, needing little more than sharp drainage to thrive for years.