Tephrocactus weberi was first described in 1936 as Opuntia weberi.
Tephrocactus weberi (Speg.) Backeb.
Opuntia weberi, Tephrocactus weberi var. weberi, Ursopuntia textoris
Tephrocactus weberi is a small shrubby cactus with segmented stems covered with conspicuous rhomboid, spirally arranged tubercles that bear small areoles with shimmering scarlet-crimson spines. It can grow up to 8 inches (20 cm) tall and branches from the base and higher-up stem segments. The stem segments are cylindrical, up to 4 inches (10 cm) long, and 1 inch (2.5 cm) in diameter. Each areole bears 3 to 10 needle-like spines that can reach up to 2 inches (5 cm) in length. There are also a few reddish glochids.
During the summer, Tephrocactus weberi produces beautiful flowers that range from yellow and orangish-yellow to pinkish and red. The flowers are up to 1 inch (2.5 cm) long and 1.6 inches (4 cm) in diameter and appear at the tips of the higher-up stem segments. The pericarpel of the flower is ovoid, tuberculate, and densely covered with spines. The fruits are spiny, nearly spherical, and about 0.4 inches (1 cm) in diameter.
Tephrocactus weberi is native to Argentina. It grows on rocky slopes in Salta, Catamarca, Tucumán, La Rioja, and San Juan provinces.
How to Grow and Care for Tephrocactus weberi
Light: Tephrocactus weberi thrives in full sun, but some shade during midday and afternoon can prevent sunburn during summer. A window that receives sunlight 6 hours a day works best when grown indoors.
Soil: This cactus requires a soil mix that drains well. So, use a commercial cactus potting mix or create your own.
Temperature: Extremely tolerant of high temperatures, Tephrocactus weberi prefers cooler temperatures in winter. It grows best in USDA Plant Hardiness Zones 9a to 11b, with average minimum winter temperatures ranging from 20 to 50 °F (-6.7 to 10 °C).
Watering: From spring to fall, water moderately and let the soil dry out completely before watering again. In most areas, rainfall will be enough for established plants. If potted, never let the container sit in water. During the winter, suspend the watering.
Fertilizing: Tephrocactus weberi does not need fertilizer when planted in the ground. However, when grown in a container, the plant will benefit from water-soluble fertilizer during the growing season. Suspend the feeding during the winter when it goes dormant.
Repotting: Repot only when the cactus becomes potbound or is too large and unstable in its container. Choose a slightly larger container with drainage holes at the bottom. The best time for repotting is late winter or early spring.
Propagation: You can propagate Tephrocactus weberi by stem segments or seeds. Using stem segments is the easiest method and yields faster results. For best results, take stem segments in early summer. Sow the seeds in late spring.
Learn more at How to Grow and Care for Opuntia.
Toxicity of Tephrocactus weberi
Tephrocactus weberi is not toxic to humans or pets. However, keep the plant away from pets and children as it has harmful spines and glochids that may cause skin irritation.
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