Echinocereus websterianus, often called Webster’s Hedgehog Cactus or San Pedro Nolasco Hedgehog Cactus, is a captivating species cherished by cactus collectors for its distinctive appearance and vibrant flowers. This columnar cactus brings a unique aesthetic to any collection, whether grown in containers or as part of a desert landscape.
Identifying Echinocereus websterianus
Echinocereus websterianus is characterized by light green, columnar stems up to 60 cm tall and 6-8 cm in diameter. These stems feature 18 to 24 low, well-defined ribs. The plant often forms clumps, though cultivated specimens may remain solitary.
Its spines are golden yellow, maturing to brownish, or occasionally white. These fragile, slightly recurved spines include 10 to 14 spreading radial spines and 6 to 8 erect central spines, up to 1 cm long. Echinocereus websterianus is native to northwestern Mexico, found on islands in the Gulf of California such as San Pedro Nolasco, Isla San Lorenzo Sur, and Isla Las Ánimas, growing on rocky slopes.
Optimal Growing Conditions
Echinocereus websterianus thrives in conditions that mimic its natural arid habitat, requiring ample sunlight for health and flowering. Full sun is ideal for outdoor cultivation. For indoor plants, a south-facing window provides bright light.
This cactus requires well-draining soil to prevent root rot. A specialized cactus or succulent mix is recommended. A deep pot benefits its root system.
Watering should follow a “soak and dry” method. During its growing season (March to October), water regularly, every two weeks. Reduce watering significantly in winter, as the plant becomes prone to rot during dormancy.
Echinocereus websterianus prefers warm daytime temperatures and can tolerate cooler nights. While it enjoys dry air, it is sensitive to frost and should be protected from freezing temperatures, though it can endure brief periods down to -5°C (23°F). A harsh, dry, and cool winter environment with maximum light exposure enhances spring flower production.
Fertilization should be minimal. A diluted, low-nitrogen cactus fertilizer can be applied once a month or every six weeks during the spring growing season. Over-fertilizing is detrimental.
Propagation Techniques
Propagating Echinocereus websterianus is done by offsets or seeds. Offsets offer quicker new plants. To propagate, remove an offset from the parent plant.
Allow the cut surface to dry and form a callus for several days to prevent rot. Once callused, plant the offset in a well-draining cactus mix, burying about one-quarter of the stem, and keep it in a warm, bright spot.
Seed propagation is slower. Seeds can be sown in a shallow container filled with a cactus soil mix. Maintain warmth and slight dampness, as germination occurs within two to three weeks. Seedlings should be kept in dappled shade initially and watered gently to avoid disturbing their delicate roots.
Common Issues and Solutions
Growers of Echinocereus websterianus may encounter issues, mainly from improper watering and light. Overwatering is a common problem, leading to root rot, especially during winter dormancy. Ensure the soil is thoroughly dry before rewatering, and reduce water frequency significantly in cooler months. Conversely, prolonged underwatering can cause the plant to shrivel, requiring more consistent moisture during its active growth phase.
Insufficient light can result in etiolation, causing the cactus to stretch and become pale. Correct this by gradually moving the plant to a brighter location with full sun exposure.
Pests such as mealybugs and spider mites affect Echinocereus websterianus. Regular inspection detects these pests early, allowing treatment with appropriate insecticidal soaps or horticultural oils.
Unique Characteristics: Flowers and Fruit
Echinocereus websterianus produces diurnal, funnel-shaped blooms near the stem’s apex. Colors vary from whitish to pink, violet, or yellowish, often with a white or yellow throat. The flowers are relatively small for an Echinocereus, up to 6 cm long and 3-4 cm in diameter.
Blooming occurs annually in June or July, with flowers remaining open for two or three days. Plants begin flowering once they reach maturity, between 7 to 10 years after sowing. Floral remains can be difficult to detach, potentially leading to stem rot if not carefully managed. While the fruit is spherical to ovoid and green to red, it is primarily visual, not edible.