Euphorbia horrida, often called the African Milk Barrel, is a popular succulent known for its cactus-like appearance. Its ribbed, cylindrical stems are typically blue-green to gray-green and covered with stout, sharp spines. Native to the semi-arid regions of South Africa, this plant stores water in its thick stems to thrive in dry climates. Its sculptural form and low-maintenance needs make it a popular choice for succulent collectors and a striking addition to any plant collection.
Essential Care Requirements
Euphorbia horrida thrives in bright, direct sunlight, needing at least six hours daily. Place it in a south-facing window indoors or a sunny outdoor area. While it tolerates intense light, very hot afternoon sun can cause scorching; provide some afternoon shade in hotter climates. Insufficient light can lead to etiolation, causing the plant to stretch and become pale.
Correct watering is crucial for Euphorbia horrida, as it is highly susceptible to root rot from overwatering. Use the “soak and dry” method: water thoroughly until it drains from the pot, then allow the soil to dry completely before watering again. During its active growing season (spring and summer), water every two to three weeks. In dormant winter months, reduce watering to once a month or less.
Euphorbia horrida requires a well-draining, gritty soil mix to prevent waterlogged roots. A specialized cactus or succulent potting mix is ideal, often amended with perlite, pumice, or coarse sand to enhance drainage. This soil allows water to flow through easily, preventing moisture from lingering around the roots. Planting in ordinary soil can lead to compacted roots, stunted growth, and increased risk of root rot.
Euphorbia horrida prefers warm temperatures, ideally 65°F to 85°F (18°C to 29°C). It can tolerate temperatures down to about 25°F (-4°C) if kept dry, but protect it from freezing. Good air circulation is beneficial, helping prevent fungal issues in stagnant, humid environments.
Fertilizing is not a primary requirement for Euphorbia horrida, as it is not a heavy feeder. If desired, apply a balanced, water-soluble fertilizer diluted to half strength sparingly during the active growing season (spring and summer). Fertilizing once a month during this period is sufficient. Avoid fertilizing during the dormant fall and winter months, as the plant is not actively growing and heavy fertilization can be detrimental.
Potting and Repotting
When choosing a pot for Euphorbia horrida, select one with ample drainage holes to facilitate water runoff. Terracotta pots are often preferred due to their porous nature, which allows for better air circulation around the roots and helps the soil dry out more quickly. Proper drainage is essential for this succulent’s health.
Repotting is typically needed when the plant becomes root-bound or the soil degrades. The ideal time is spring or early summer, as the plant enters its active growth phase. When repotting, carefully remove the plant from its container, being gentle with the root system. Choose a pot only slightly larger than the previous one, ensuring adequate room for growth without holding excessive moisture. After repotting, wait a few days before the first watering to allow any root damage to heal.
Propagation
Euphorbia horrida can be propagated from offsets, often called “pups,” that form around the base of the main plant. To propagate, carefully remove a healthy offset from the parent plant using clean, sharp tools. Wear gloves during this process due to the plant’s sap.
After separating the offset, allow the cut end to dry and form a callus for several days before planting. This callusing prevents rot once the offset is placed in soil. Plant the callused offset in a well-draining succulent soil mix. Water sparingly until roots establish, providing just enough moisture to encourage growth without risking rot.
Troubleshooting Common Problems
Root rot is a common problem for Euphorbia horrida, manifesting as mushy stems and discoloration. It is almost always caused by overwatering or poorly draining soil, leading to roots sitting in excessive moisture. Prevent it by adhering to the “soak and dry” method and using appropriate soil. If root rot occurs, prune affected parts and repot the plant into fresh, dry soil.
Etiolation, characterized by stretched, leggy, and pale growth, indicates insufficient light. The plant elongates as it strains to find more light. Moving the plant to a brighter location with more direct sunlight will encourage compact, healthy new growth.
While generally resilient, Euphorbia horrida can occasionally be affected by common succulent pests like mealybugs and spider mites. These pests often appear as small, white, cottony masses or fine webbing. Treat affected areas by wiping with a cotton swab dipped in rubbing alcohol or applying insecticidal soap, ensuring thorough coverage.
Wrinkling or shrinking of the stems can be a sign of underwatering. This can also occur during the plant’s natural dormancy period in winter. Increase watering frequency slightly, ensuring the soil dries out between waterings, to resolve this issue.
Safety Considerations
All Euphorbia species, including Euphorbia horrida, produce a milky white latex sap when cut or damaged. This sap is a known skin and eye irritant, causing inflammation and allergic reactions upon contact. Ingestion is toxic and can lead to severe irritation of mucous membranes.
When handling Euphorbia horrida, especially during repotting or propagation, wear protective gloves and eye protection. If accidental contact with sap occurs, immediately wash affected skin thoroughly with soap and water. If sap enters the eyes, flush them immediately with plenty of water for at least 15 minutes and seek prompt medical attention, as severe irritation or temporary vision impairment can result. Keep Euphorbia horrida plants out of reach of children and pets.