About
Canna 'Black Knight' is a robust perennial that can reach heights of up to 1.8 meters. It features large leaves that exhibit a bronze to bluish-purple hue. Throughout midsummer to autumn, it produces deep red flowers that can measure up to 8 centimeters in diameter. This plant is well-suited for creating a tropical-themed border.
About the genus
Canna are herbaceous perennials characterized by their rhizomatous growth and upright stems. They feature broad, oval leaves and prominent flowers that include petal-like staminodes along with smaller, colored petals and sepals. These blooms appear in clusters, such as racemes or panicles, during the summer and autumn months.
Growing conditions
- Sunlight
- Full sun
- Soil type
- Loam, Sand
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Moist but well-drained
- Aspect
- South-facing, West-facing
- Exposure
- Sheltered
- UK hardiness
- H3
Plant details
- Plant type
- Herbaceous Perennial
- Habit
- Columnar upright
- Foliage
- Deciduous
- Height
- 1.5-2.5 metres
- Spread
- 1-1.5 metres
- Time to full height
- 2-5 years
- Suggested uses
- Architectural, City and courtyard gardens, Cottage and informal garden, Patio and container plants, Sub-tropical
Care notes
- Cultivation
- Grow in a sheltered site with full sun. Water freely in dry spells and apply a balanced liquid feed monthly. In cold regions, lift the rhizomes in autumn once frost has blackened the foliage and store in barely moist compost in frost-free conditions. In areas that are frost-free or almost so, leave in situ and protect with a deep dry mulch. See canna cultivation for further information
- Pruning
- No pruning necessary, deadhead flowers to prolong flowering
- Propagation
- Propagate by division of rhizomes in spring
- Pest resistance
- May be susceptible to slugs and snails, aphids and glasshouse red spider mite
- Disease resistance
- May be susceptible to Canna viruses