Euphorbia horrida (African Milk Barrel)

Euphorbia horrida (African Milk Barrel) is a resilient and visually striking plant that offers both aesthetic and practical benefits to gardens and landscapes. Its unique appearance, combined with its low maintenance needs and adaptability to harsh conditions, make it an excellent choice for gardeners looking to add a touch of the exotic to their outdoor spaces.

Euphorbia horrida – African Milk Barrel: An In-depth Look

Euphorbia horrida, commonly known as the African Milk Barrel, is a striking succulent that is known for its cylindrical, ribbed stems which are typically blue-green to grey-green in color and covered with stout, sharp spines that can be brown, black, or grey. The spines are actually modified stipules that give the plant a formidable appearance. Euphorbia horrida has a somewhat columnar growth habit and can form dense clumps over time.

Native: Euphorbia horrida is native to South Africa, particularly the Cape Province region. It thrives in the semi-arid, rocky regions of this area, where it has adapted to survive with minimal water and harsh sunlight. It belongs to the spurge family, Euphorbiaceae.

Plant Type and Habit: This plant is a perennial succulent with a columnar habit. It typically grows upright, forming single or multiple stems that can eventually develop into a dense clump. It is slow-growing but can reach substantial sizes over many years.

Size: African Milk Barrel can grow up to 3 feet (90 cm) in height and about 1 to 2 feet (30 to 60 cm) in spread. The individual stems are usually about 3 to 5 inches (8 to 12 cm) in diameter. The size of the plant can vary depending on growing conditions and age.

Flowers: The flowers of Euphorbia horrida are small, inconspicuous, and typically yellow-green. They are cyathia, a type of inflorescence unique to the spurge family, and appear at the tips of the stems. While not particularly showy, the flowers add a subtle charm to the plant. They generally bloom in the summer months. The fruits of Euphorbia horrida are small, dry capsules that contain tiny seeds. These fruits are not particularly ornamental and are often overlooked.

Body: The body of the African Milk Barrel consists of cylindrical, ribbed stems that are densely covered with sharp spines. The ribs are well-defined and give the plant a segmented appearance. The coloration of the stems can range from blue-green to grey-green, often with a waxy coating that helps reduce water loss.

Uses: This plant is primarily used as an ornamental in succulent gardens, rock gardens, and container plantings. Its unique, spiny appearance makes it a focal point in any landscape. Euphorbia horrida can also be grown indoors as a houseplant, provided it receives plenty of light and is planted in well-draining soil.

Hardiness: Euphorbia horrida is hardy in USDA zones 9 to 11. It can tolerate temperatures down to about 25°F (-4°C) if kept dry, but it prefers warmer climates. In regions with colder winters, it should be grown in containers that can be moved indoors or provided with frost protection.

Award: Recipient of the prestigious Award of Garden Merit of the Royal Horticultural Society.

Toxicity: Euphorbia horrida contains a milky latex sap that is toxic and can cause skin irritation or allergic reactions. The sap can be harmful if ingested and can cause severe irritation if it comes into contact with the eyes. It is important to handle the plant with care, wearing gloves and avoiding contact with the sap.

Wildlife: In its native habitat, Euphorbia horrida provides shelter for small insects and animals. The flowers attract pollinators such as bees and other insects.

Deer and Rabbit: Generally resistant to deer and rabbits, due to its toxic sap.

Drought: Euphorbia horrida is highly drought-tolerant, an essential adaptation for survival in its native semi-arid environment. The plant stores water in its thick, fleshy stems and requires minimal watering once established. It thrives in dry conditions and can tolerate extended periods without water.

Invasiveness: Euphorbia horrida is not considered invasive. It grows slowly and does not spread aggressively. While it may produce offsets, these are relatively few and can be easily managed or transplanted to new locations.

Benefits: The primary benefits include its low maintenance requirements, drought tolerance, and unique aesthetic appeal. It adds a dramatic, architectural element to gardens and landscapes, particularly in xeriscapes and rock gardens. The plant’s resistance to deer and rabbits, combined with its ability to thrive in poor soil conditions, makes it a resilient choice for challenging environments.

African Milk Barrel Growing Tips

Light: Prefers full sun to partial shade. Needs at least 6 hours of direct sunlight daily. Avoid intense afternoon sun.

Soil: Requires well-draining soil, such as cactus or succulent mix. Adding sand or perlite can improve drainage.

Water: Water sparingly; allow soil to dry completely between waterings. Reduce watering in winter when the plant is dormant.

Fertilizer: Fertilize sparingly with a diluted, balanced fertilizer during the growing season (spring and summer). Once a month is sufficient.

Pruning: Pruning is not necessary. Remove any dead or damaged parts as needed.

Propagation: Propagate by cuttings or offsets. Allow cuttings to dry for a few days before planting.

Pests and Diseases: Generally pest-resistant but watch for pests like mealybugs or aphids. Overwatering can lead to root rot, so ensure proper drainage.