The “middle finger cactus” is an informal name for various cacti with a striking appearance. This moniker typically refers to types of cacti that exhibit upright, columnar, or finger-like growth habits. Though not a botanical classification, the term highlights their striking visual characteristics.
Unique Characteristics
The common name “middle finger cactus” applies to species like Stenocereus thurberi, known as the Organ Pipe Cactus, and Mammillaria elongata, or Ladyfinger Cactus. Stenocereus thurberi features tall, slender, cylindrical stems, dark green to gray-green, often branching from the base, resembling organ pipes. Stems can reach impressive heights with gray to brown spines up to 1 inch.
Mammillaria elongata is smaller, forming dense clumps of elongated, finger-like stems up to 6 inches tall. Covered with short, interlocking spines. Both are native to arid regions; Stenocereus thurberi in the Sonoran Desert and Mammillaria elongata in central Mexico.
Essential Care Guidelines
Proper care for these cacti mimics their native arid environments, focusing on light, soil, and watering. Both Stenocereus thurberi and Mammillaria elongata thrive in full sun, requiring at least 6 to 8 hours of direct sunlight daily. Indoors, a south-facing window provides necessary intense light.
Well-draining soil is crucial to prevent root rot. A sandy or gritty cactus mix, enhanced with perlite or pumice, is ideal. Avoid heavy or clay soils, as they retain too much moisture.
Water infrequently but thoroughly, allowing the soil to dry completely between applications. During the spring and summer growing season, water deeply until drainage occurs. In winter dormancy, reduce or suspend watering.
These cacti prefer warm temperatures and low humidity. Stenocereus thurberi thrives between 65°F and 100°F (18°C to 38°C). Both species are not frost-tolerant and require protection from freezing conditions.
Fertilization is minimal; apply a balanced cactus fertilizer sparingly during the growing season. Mammillaria elongata may need it monthly, Stenocereus thurberi annually in spring. Pots must have drainage holes; unglazed clay pots are recommended as they wick away excess moisture. Mammillaria elongata may need repotting every two to three years, but Stenocereus thurberi rarely requires it.
Propagation and Common Challenges
Propagating these cacti is commonly achieved through stem cuttings. Select a healthy stem section, at least 4 inches long, and use a clean, sharp knife. Allow the cut end to dry and form a callus, preventing rot. Once callused, plant into a well-draining cactus mix.
Water lightly after planting, then only when the soil is completely dry. Keep in a warm spot with indirect light until roots establish. Mammillaria elongata can also be propagated by separating offsets from the parent plant.
Despite their resilience, cacti can face common challenges. Overwatering is a common problem, leading to soft, mushy stems, yellowing, and root rot, which can be fatal. Prevent overwatering by adhering to a “soak and dry” schedule, allowing the soil to dry completely between waterings. Underwatering causes shriveling or discoloration. Gradually reintroduce water to rehydrate.
Pests can also affect cacti, though generally less susceptible than other plants. Common pests include mealybugs, spider mites, scale insects, and fungus gnats. Treat with rubbing alcohol, insecticidal soap, or neem oil.
Lack of flowering indicates unmet environmental conditions. For Mammillaria elongata, a cool, dry winter resting period encourages spring blooming. Stenocereus thurberi flowers only upon maturity, which can take around 35 years.