Alternanthera dentata 'Little Ruby'

Little Ruby Alternanthera

Botanical Name: Alternanthera dentata ‘Little Ruby’
Family: Amaranthaceae
Origin: Tropical & sub-tropical Americas (cultivar selection)
Plant Type: Evergreen to semi-evergreen perennial groundcover/subshrub

Overview

A compact, richly coloured foliage plant perfect for adding bold contrast to Adelaide and South Australian gardens. Alternanthera ‘Little Ruby’ forms a low, dense mound of deep burgundy foliage that holds its colour beautifully through the warm months. Far more sun- and heat-tolerant than older Alternanthera forms, it thrives in Adelaide’s Mediterranean climate when given protection from harsh afternoon sun. Its fine roots, compact habit, and year-round colour make it ideal for borders, mass planting, tropical-themed spaces, alfresco pots and pathways. Not fragrant, but valued for its intense leaf colour and reliable structure.

Key Features

• Mature Size: 0.3–0.4 m H × 0.5–0.9 m W – dense, spreading cushion
  
• Growth Rate: 20-30 cm per year under good conditions
• Foliage: Glossy, rich burgundy to deep plum-purple leaves; may develop brighter red tints in strong light and bronze or duller tones in winter cold
• Flowers: Tiny, cream-white inconspicuous clusters in warm months (ornamentally insignificant)
  
• Seasonal Interest: Year-round foliage colour, with the most intense burgundy tones in warm seasons
• Wildlife Value: Light flowers may attract small beneficial insects
• Tolerance: Heat-tolerant (with afternoon shade), drought-tolerant once established, wind-tolerant, light frost sensitive (may defoliate if exposed; recovers in spring); not coastal-front tolerant but fine in sheltered coastal suburbs
• Planting Density: Mass planting: 4–6 plants per m²; Borders/edges: 30–40 cm apart
• Pet Friendly: Generally non-toxic to cats and dogs

Where It Works Best

• Sunlight: Best in morning sun + afternoon shade; tolerates full sun near the coast; inland full sun may scorch foliage
• Soil: Free-draining loam or sandy soil enriched with organic matter; avoid waterloggin
• Water Needs: Establishment: 2 deep soaks/week for 8–10 weeks. Established: deep soak every 10–14 days in summer; weekly in heatwaves; minimal water in winter
• Maintenance: Low-maintenance — trim lightly in late winter/early spring to maintain shape and encourage dense new growth; mulch well; optional slow-release fertiliser in spring
• Lifespan: 4–8+ years in suitable SA conditions
• Climate Zones: Suited to Adelaide Plains, Hills foothills, coastal suburbs; protect from frost-prone inland hollows
• Soil pH: Neutral to slightly acidic; tolerates mildly alkaline SA soils

Landscape & Design Ideas

• Mass planting for a carpet of dramatic burgundy colour
• Border edging along paths, driveways and front gardens
• Tropical or Mediterranean colour accents paired with lime greens, silvers or gold foliage
• Striking underplanting around feature trees (in part shade)
• Alfresco pots and courtyard displays for year-round colour contrast

Why You Will Love It

‘Little Ruby’ gives your garden an instant colour lift — lush, deep burgundy foliage that performs beautifully in Adelaide’s challenging heat when given partial shade. Compact, tidy, and dependable, it’s perfect for borders, pots, mass planting and modern garden palettes needing rich contrast with very little fuss.