The Longhorn Plant (Stapelia gigantea) is a distinctive succulent known for its unique appearance and intriguing floral characteristics. It offers a captivating addition to any collection, particularly for those interested in unusual botanical specimens.
Identifying the Longhorn Plant
The Longhorn Plant, also known as Giant Carrion Flower, Starfish Flower, and Zulu Giant, is native to arid Southern Africa, including Mozambique, South Africa, and Swaziland. It forms clump-like growths with erect, four-angled stems up to 25 cm (10 inches) in height. Stems are typically green but may turn reddish-purple in direct sunlight.
Its most striking feature is its large, star-shaped flowers, measuring 25 to 40 cm (10-16 inches) in diameter, making them among the largest flowers in the succulent world. These five-petaled blooms are pale ochre-yellow with maroon striations, giving them a wrinkled, leathery texture. The flower margins are fringed with fine hairs up to 8 mm long. A strong odor resembling rotting meat attracts carrion flies for pollination, often leading flies to lay eggs on the flowers.
Longhorn Plant Care
Providing optimal care for the Longhorn Plant ensures its health and encourages its unique blooms. This succulent thrives in environments that mimic its natural arid habitat.
The plant requires bright, indirect light to flourish. While it can tolerate some direct morning or late afternoon sun, intense midday sun can lead to burning or discoloration of the stems. If grown indoors, a south-facing window is often suitable, but protection from harsh, direct rays is still beneficial.
A well-draining soil mix is essential for Stapelia gigantea, as it is highly susceptible to root rot. A specialized succulent or cactus mix, amended with perlite, pumice, or coarse sand, provides necessary drainage and aeration. Smaller, shallower terra-cotta pots are often suitable as they help reduce excess moisture.
Watering should follow a “soak and dry” method, allowing the soil to dry out completely between waterings. During the active growing season in spring and summer, watering may occur every one to three weeks. In contrast, watering should be significantly reduced or ceased entirely during the plant’s dormant period in fall and winter to prevent rot. Under-watering is generally preferred over overwatering for this succulent.
The Longhorn Plant prefers warm temperatures, ideally ranging between 21°C to 29°C (70°F to 85°F) during its growing season. It can tolerate slightly cooler temperatures, but prolonged exposure below 10°C (50°F) can be detrimental, and it is sensitive to frost. Typical indoor humidity levels are generally sufficient, as the plant thrives in low humidity environments.
Fertilization should be minimal and only applied during the active growing season. A balanced, water-soluble fertilizer diluted to half strength, applied approximately once a month, can support healthy growth and flowering. Over-fertilization can harm the plant, and it is not necessary to fertilize during the dormant autumn and winter months.
Propagating Longhorn Plant
Propagating the Longhorn Plant is commonly achieved through stem cuttings. The best time to take cuttings is during the plant’s active growing season, typically from spring through summer.
To propagate, select a healthy, mature stem and use a clean, sharp knife or scissors to make a clean cut. Allow the severed end to dry and “callus over” for several days before planting. This callusing process helps prevent rot once the cutting is placed in soil. Once the cut surface has formed a dry seal, plant the cutting in a well-draining succulent or cactus mix. Water sparingly until roots establish, which can take several weeks to a few months.
Addressing Longhorn Plant Problems
Several common issues can affect the Longhorn Plant, but most can be managed with proper care adjustments.
Root Rot
Root rot is a frequent concern, primarily caused by overwatering or poorly draining soil. Symptoms include mushy stems and wilting. To prevent this, ensure the soil dries completely between waterings and use a gritty, well-draining mix. If root rot is suspected, unpot the plant, remove affected sections, allow to callus, and repot in fresh, dry soil.
Lack of Flowering
Lack of flowering can occur if the plant does not receive sufficient light or experiences improper dormancy. The plant flowers most prolifically in late summer or fall, often triggered by shortening daylight hours. Providing bright, indirect light during the growing season and a cooler, drier rest period in winter can encourage blooming.
Pests
Pests, particularly mealybugs, can infest the Longhorn Plant. These small, white, cottony insects can be found on stems and in crevices. Treatment options include wiping them off with a cotton swab dipped in rubbing alcohol or applying insecticidal soap.
Leggy Growth
Leggy growth, characterized by stretched and elongated stems, indicates insufficient light. The stems may also appear paler than usual. Moving the plant to a location with brighter, indirect light can help correct this issue and promote more compact growth.