The Euphorbia trigona ‘Royal Red’ is an appealing succulent known for its unique form and striking coloration. Often called African Milk Tree, Good Luck Plant, or Cathedral Cactus, it is a popular, low-maintenance choice for indoor growers.
Key Characteristics
The Euphorbia trigona ‘Royal Red’ features upright, columnar stems, typically three- or four-sided, displaying green with prominent reddish-purple to magenta edges and V-shaped patterns that become more pronounced with adequate light. Small, teardrop-shaped leaves emerge from between reddish-brown spines along the stem ridges. Though often mistaken for a cactus, it is a euphorbia, a distinct plant family.
Essential Care Practices
Light Requirements
Euphorbia trigona ‘Royal Red’ thrives in bright, indirect light, needing at least four to six hours daily. Placing it near a south, east, or west-facing window is suitable. While it can tolerate some direct morning or late afternoon sun, intense midday sunlight can cause scorching. Insufficient light may lead to paler stems, less vibrant red coloration, and leggy growth.
Watering Needs
This succulent prefers a “soak and dry” watering method, meaning the soil dries completely between waterings. Overwatering quickly leads to root rot. During spring and summer, water thoroughly until it drains from the pot bottom, typically every 10 to 14 days or when the top one to two inches of soil are dry. In dormant fall and winter, reduce watering significantly, to once every three to four weeks.
Soil Mix
A well-draining soil mix is essential for Euphorbia trigona ‘Royal Red’ to prevent waterlogging. A specialized succulent or cactus potting mix is ideal. You can enhance drainage by amending a standard potting mix with perlite, pumice, or coarse sand. Ensure the pot has adequate drainage holes.
Temperature and Humidity
Euphorbia trigona ‘Royal Red’ prefers warm temperatures, between 65°F and 85°F (18°C to 29°C). While it can tolerate brief temperature drops, it is not frost-hardy and should be protected from temperatures below 40°F (4°C). In colder climates, bring the plant indoors during winter. This plant is well-adapted to average household humidity levels and does not require additional humidity. Avoiding cold drafts is beneficial.
Fertilization
During spring and summer, Euphorbia trigona ‘Royal Red’ benefits from occasional fertilization. Use a balanced liquid fertilizer for cacti and succulents, diluted to half strength. Applying fertilizer once a month during this period is sufficient. Avoid over-fertilizing, which can lead to leggy growth or root damage. Do not fertilize during fall and winter dormancy.
Propagation Techniques
Propagating Euphorbia trigona ‘Royal Red’ is achieved through stem cuttings. Select a healthy stem and use a clean, sharp knife to make a cut. Allow the cut end to dry and form a callus for three to seven days before planting; this callusing prevents rot. Plant the callused cutting in a well-draining succulent or cactus mix, inserting it a few inches deep. Water sparingly until new growth indicates rooting has occurred.
Troubleshooting Common Problems
Leaf drop in Euphorbia trigona ‘Royal Red’ can result from insufficient light or improper watering (too much or too little). Adjusting light exposure and ensuring the soil dries out between waterings helps mitigate this. Stem rot, characterized by mushy or discolored stems, results from overwatering or poorly draining soil. To address this, improve drainage and adjust watering frequency; in severe cases, affected parts may require removal.
Pest infestations, including mealybugs and spider mites, can occur. Mealybugs appear as small, white, cottony masses; spider mites cause yellowing leaves and fine webbing. Address these pests by wiping them with a damp cloth or using an insecticidal soap. Adequate air circulation also helps deter pests.
Safety Considerations
Handle Euphorbia trigona ‘Royal Red’ with care due to its milky white sap, also known as latex. This sap can irritate skin, causing rashes or blistering. If sap gets into eyes, it can cause severe irritation, pain, and blurred vision, requiring immediate rinsing and medical attention. The sap is also toxic if ingested, leading to gastrointestinal upset in humans and pets. Wear gloves when handling the plant, especially during pruning or propagation, and keep it out of reach of children and pets.