Pennisetum advena 'Rubrum'

Purple Fountain Grass

Botanical Name: Pennisetum advena ‘Rubrum’
Family: Poaceae
Origin: Africa / Tropical regions (cultivar selection)
Plant Type: Evergreen to semi-evergreen ornamental grass (semi-evergreen in SA)

Overview

A striking warm-season ornamental grass for Adelaide’s Mediterranean climate, Pennisetum advena ‘Rubrum’ is treasured for its deep burgundy foliage and graceful arching plumes that appear from late spring through autumn. Soft, fluffy, pinkish-purple flower spikes sway beautifully in the slightest breeze, giving movement and texture to borders, modern landscapes and feature pots.
Foliage deepens to rich wine tones in full sun and may develop bronzy or dusky tints during cold spells. While not fragrant, the plumes have a soft, tactile quality that enhances sensory gardens. Exceptionally heat-tolerant and low-maintenance, it thrives in South Australia’s dry summers when planted in free-draining soil.

Key Features

• Mature Size: 1.0–1.5 m H × 0.8–1.2 m W (arching fountain form)
• Growth Rate: 40–60 cm+ per year in warm conditions
• Foliage: Deep burgundy to wine-red strappy leaves; may bronze or dull slightly in cold weather; recovers colour in warmth
• Flowers: Soft, foxtail plumes in pink–purple tones from late spring to late autumn; heaviest flush late summer
• Fragrance: Not fragrant — plumes have a pleasant, tactile, velvety feel rather than scent
  
• Seasonal Interest: Rich burgundy foliage all warm season → fluffy plumes from late spring–autumn → foliage may partially die back or dull in winter → strong regrowth in spring
• Wildlife Value: Plumes attract seed-eating birds; excellent habitat for beneficial insects; movement provides shelter for small garden fauna
• Tolerance: Heat-tolerant; drought-tolerant once established; wind-tolerant; coastal-tolerant (second-line); light frost hardy in Adelaide (foliage may burn but regrows in spring); dislikes waterlogged soils
• Planting Density: 2–3 plants per m² for mass planting; 80–100 cm spacing in borders; suitable for large pots (40–50 cm+)
• Pet Friendly: Non-toxic to cats and dogs; plumes may be tempting for play but are harmless

Where It Works Best

• Sunlight: Full sun essential for deepest colour; tolerates very light part shade but foliage turns greener
• Soil: Free-draining sandy, loamy or gravelly soils; thrives in slightly alkaline ground typical of Adelaide
• Water Needs: Establishment: 2 deep soaks/week for 8–12 weeks. Established: deep soak every 10–14 days in summer; minimal watering needed in cooler months
• Maintenance: Cut back hard to 20–30 cm in late winter to refresh foliage; remove spent plumes; avoid over-fertilising (encourages green over burgundy)
• Lifespan: 3–5+ years (longer in mild winters; evergreen in warm microclimates)
• Climate Zones: Ideal for Mediterranean and temperate SA — Adelaide Plains, foothills, Fleurieu, Yorke Peninsula, coastal suburbs
• Soil pH: Neutral to alkaline; tolerates slightly acidic soils with good drainage

Landscape & Design Ideas

• Architectural foliage and plumes for modern, Mediterranean or coastal plantings
• Mass plant for a flowing, kinetic effect with movement and light-play
• Combine with Salvias ‘Mystic Spires’, ‘Amistad’, Gaura, Catmint and Agastache for vibrant, long-season colour
• Striking focal grass in large containers for alfresco areas
• Softens retaining walls, paths and hot reflective spaces

Why You Will Love It

‘Rubrum’ turns any sunny Adelaide garden into a warm, textural, high-impact landscape feature. With rich burgundy foliage, months of feathery plumes, superb heat tolerance and virtually no maintenance, it delivers beauty, movement and colour through the entire warm season.