The “Devil’s Beard Plant” refers to Chasmanthe aethiopica, a species originating from South Africa. Also known as small cobra lily or African cornflag, this plant presents a unique duality: it is valued for its vibrant ornamental appeal, yet its vigorous growth can lead to invasive tendencies in certain climates. Its striking flowers and easy cultivation make it a popular garden choice, particularly in Mediterranean-type climates where it readily naturalizes. However, its rapid spread can outcompete native flora in some regions.
Identifying Devil’s Beard
Chasmanthe aethiopica is a cormous herbaceous perennial, typically growing to 0.4 to 0.65 meters, though some can reach up to 1 meter. Its distinctive flowers are vibrant orange-red to deep orange, appearing in a spike formation. These tubular, trumpet-shaped flowers have a slender, twisted base that widens into a cylindrical upper portion.
The flowers are arranged in an unbranched spike, with all blooms often facing to one side, curving outwards in a double row along the upper stem. The upper petal segment is spoon-shaped and held horizontally over the stamens (25-35 mm long), while lower petals are shorter (10-15 mm). Blooming occurs from autumn to winter (April to July), providing early garden color.
The leaves are pale green, sword-like or strap-like, and soft-textured, often with a prominent midvein. Arranged in a fan-shaped basal clump, leaves grow 30-45 cm long and 1.2-2 cm wide. It grows from globose underground corms, covered in brown tunics, which enable its perennial and clump-forming habit.
Growing Devil’s Beard
Chasmanthe aethiopica thrives in winter-rainfall areas, mimicking its native South African habitat. It prefers full sun to partial shade, flowering best in sunny locations. This adaptability makes it suitable for underplanting beneath deciduous trees.
It prefers fertile, freely draining soil, tolerating sandy, loamy, and clay types if drainage is good. Adding sand and organic matter prevents waterlogging and corm rot. It adapts to a wide pH range (acid to alkaline).
As a winter-growing plant, it requires regular watering during its autumn and winter active season, but must be kept dry during summer dormancy. While it tolerates some dormancy moisture in well-drained soil, avoid excessive wetness. Apply slow-release fertilizer during the growing period for optimal flowering.
Semi-frost hardy, it tolerates temperatures down to -5°C. It is best suited for USDA zones 8-11, thriving in Mediterranean, subtropical, or desert climates. In colder regions, grow it in pots for frost protection.
Managing Devil’s Beard
Chasmanthe aethiopica can become problematic due to its vigorous growth and ability to naturalize easily outside its native range. Its rapid spread can form dense stands, potentially outcompeting native plant species. This weediness has been observed in areas like California, where it has escaped cultivation.
Manual removal involves digging up plants, ensuring all underground corms and cormlets are removed. Since parent corms produce many small cormlets, leaving any behind can lead to regrowth. Consistent effort is necessary to eliminate established populations.
For larger infestations, chemical control may be considered. Apply herbicides according to local regulations and product instructions to minimize harm to desirable plants. Selective application targeting only Chasmanthe aethiopica helps protect other vegetation.
Prevention is a key management strategy. Avoid planting this species where it is known to be invasive. Properly dispose of garden waste containing corms or seeds to prevent accidental dispersal. Regularly monitor for new growth to allow for early intervention.
Propagation and Spread
Chasmanthe aethiopica spreads rapidly through several effective methods. Primary spread occurs via cormlets. The parent corm divides, producing numerous smaller cormlets that detach and grow into new plants, forming extensive clumps.
Seed dispersal also contributes to spread. It produces pea-sized, bright orange seeds in capsules. These seeds have a fleshy, sweet coating, attracting fruit-eating birds, which disperse them to new locations.
Human activities also contribute significantly. Improper disposal of garden waste containing corms, cormlets, or seeds can introduce the plant to new areas. Contaminated soil movement during landscaping or construction can transport plant material. Intentional planting in suitable climates can lead to naturalization and spread into wildlands.