Euphorbia susannae is a unique and sought-after succulent, highly valued by collectors and plant enthusiasts. Its distinctive appearance and relatively low maintenance requirements make it an appealing addition to many plant collections.
Understanding Euphorbia Susannae
Native to the Cape Provinces of South Africa, Euphorbia susannae, often called Suzanne’s Spurge, is a small, clump-forming succulent. It typically grows in sandy, stony ground, sometimes partially underground or forming a hemispherical shape above ground.
This succulent features chubby, lime-green stem segments that mound into a dense pile. The erect, cylindrical, fleshy stems are often bright green, developing a coppery-brown flush in intense sunlight. Stems feature 12 to 16 prominent ribs lined with conical tubercles, which may wear off over time. The plant reaches up to 4 inches (10 cm) in height and spreads up to 12 inches (30 cm) in diameter. During spring and summer, it produces small, yellowish flowers, known as cyathia, at the apex of its tubercles.
Caring for Euphorbia Susannae
Light
Euphorbia susannae thrives in bright, direct sunlight, which promotes robust growth and vibrant coloration. It generally needs at least six hours of direct sunlight daily. While it can tolerate partial shade, prolonged periods in such conditions may lead to leggy growth and reduced flowering. In extremely hot climates or during intense summer heat, some protection from the harshest afternoon sun may be beneficial to prevent sunburn or discoloration. If grown indoors, a south or east-facing window providing ample bright light is suitable.
Watering
As a drought-tolerant succulent, Euphorbia susannae requires minimal moisture. Water thoroughly, then allow the soil to dry completely before rewatering. Overwatering is a common issue that can lead to root rot. During the active growing season (spring and summer), water every one to three weeks, ensuring the soil is dry several inches deep. During cooler months or dormancy, watering should be reduced significantly or suspended entirely to prevent rot.
Soil Requirements
Euphorbia susannae requires well-draining, gritty soil to prevent root rot. A specialized cactus or succulent soil mix, amended with 50% to 75% mineral grit (e.g., coarse sand, pumice, perlite), ensures adequate drainage. Using a pot with drainage holes is essential for proper water runoff.
Temperature and Humidity
Euphorbia susannae tolerates temperatures from 32°F (0°C) to 109°F (43°C). However, it does not tolerate hard frost and should be protected below 46°F (8°C) to avoid damage. In cold winter regions, bring the plant indoors or provide frost protection. It prefers low humidity and thrives in moderate temperatures.
Fertilizing
Euphorbia susannae does not require extensive fertilization for healthy growth. If fertilizing, apply a half-strength liquid fertilizer with low nitrogen (e.g., 2-7-7 formula) during the growing season. Fertilize once a month in spring and summer, stopping entirely during winter dormancy. Over-fertilization can harm the plant.
Propagating Euphorbia Susannae
Euphorbia susannae is most commonly propagated through stem cuttings. When taking cuttings, wear gloves to avoid contact with the plant’s milky sap. After making a clean cut, allow cuttings to dry and callous for two to three days before planting to prevent rot.
Once callused, place cuttings in a well-draining mixture of sand, soil, and pumice. Temperatures around 68°F (20°C) are recommended for successful rooting. While seed propagation is possible, seeds are often difficult to germinate and have short viability. Cuttings are generally a more reliable and faster method.
Common Issues and Solutions
Overwatering is a primary concern, often leading to root rot. Symptoms include mushy stems or a general decline in plant health. To remedy, ensure well-draining soil and allow the substrate to completely dry between waterings. If root rot is severe, repotting into fresh, dry, gritty soil after trimming any affected roots may be necessary.
Conversely, if the plant feels less firm or looks wrinkled, it needs water. Thorough watering will help it rehydrate. Pests like mealybugs and spider mites can occasionally affect Euphorbia susannae. Regular inspection helps detect infestations early, which can be addressed with insecticidal soap or neem oil.
Safety Considerations
Euphorbia susannae, like many other Euphorbia species, produces a milky white sap (latex) when cut or damaged. This toxic sap can cause skin irritation, rashes, blistering, and pain upon contact, and severe irritation if it enters eyes or mouth.
When handling Euphorbia susannae, especially during pruning or propagation, wear protective gloves and eye protection. If sap touches skin, wash immediately with soap and water. Keep the plant out of reach of children and pets, as ingestion can lead to gastrointestinal issues.