About
Arisaema costatum is a perennial plant that grows from tubers, reaching heights of approximately 60 cm. It features large, three-lobed leaves that can extend up to 40 cm in length, characterized by prominent ridges and purple edges. These leaves typically appear in early summer, preceding the flowering period, which lasts through the summer months. The flowers consist of a deep purple spathe shaped like a hood, adorned with white stripes, alongside a long, slender, twisted spadix.
About the genus
Arisaema consists primarily of tuberous perennials characterized by palmately lobed foliage. They feature unique tubular, hooded spathes that enclose small true flowers clustered at the base of a club-shaped or filamentous spadix. After flowering, these plants produce a spike bearing red berries.
Growing conditions
- Sunlight
- Partial shade
- Soil type
- Loam, Sand
- Soil pH
- Acid, Neutral
- Soil moisture
- Moist but well-drained
- Aspect
- East-facing, North-facing, West-facing
- Exposure
- Sheltered
- UK hardiness
- H4
Plant details
- Plant type
- Herbaceous Perennial
- Habit
- Columnar upright
- Foliage
- Deciduous
- Height
- 0.5-1 metres
- Spread
- 0.5-1 metres
- Time to full height
- 5-10 years
- Suggested uses
- Cottage and informal garden, Patio and container plants, City and courtyard gardens
- Native to
- Himalaya to S Tibet
- Toxicity
- Humans/Pets: Harmful if eaten, skin/eye irritant. Wear gloves and other protective equipment when handling For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Care notes
- Cultivation
- Plant the tubers 20cm deep in winter or spring, into moist but well-drained, humus-rich soil in a cool, partially shaded site. In colder regions it may need winter protection, mulch with well-rotted leaf mould for insulation. Tubers must not dry out while dormant but avoid excessive winter wet.
- Pruning
- No pruning required
- Propagation
- Propagate by seed sown in containers in a cold frame in autumn or spring. Offsets may be removed in late summer
- Pest resistance
- May be susceptible to slugs and vine weevil
- Disease resistance
- Generally disease-free