About
Alternanthera dentata 'Purple Knight' is a robust, upright perennial typically cultivated as an annual due to its tender nature. It features elongated, lanceolate leaves that exhibit deep purple coloration, along with infrequent, inconspicuous white flowers that appear in the summer.
About the genus
Alternanthera encompasses both bushy annuals and perennials known for their vibrant foliage and inconspicuous flowers.
Growing conditions
- Sunlight
- Full sun
- Soil type
- Chalk, Loam, Sand
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Moist but well-drained, Well-drained
- Aspect
- South-facing
- Exposure
- Sheltered
- UK hardiness
- H1C
Plant details
- Plant type
- Conservatory Greenhouse, Annual Biennial, Herbaceous Perennial
- Habit
- Bushy, Spreading branched, Columnar upright
- Foliage
- Evergreen
- Height
- 0.1-0.5 metres
- Spread
- 0.1-0.5 metres
- Time to full height
- 1-2 years
- Suggested uses
- City and courtyard gardens, Patio and container plants
Care notes
- Cultivation
- Plant in light moist but well-drained fertile soil in sheltered sunny sites as an annual. Darkest leaf colour develops in full sun. Also grown under glass in light loam compost with plenty of light, water and regular feeding.
- Pruning
- Pinch out tips and clip back to keep bushy shape
- Propagation
- Propagate by division, seed and stem tip cuttings
- Pest resistance
- May be susceptible to glasshouse red spider mite
- Disease resistance
- May be susceptible to fusarium wilt