The fan cactus, Myrtillocactus geometrizans ‘Fukurokuryuzinboku’, is a distinctive succulent. Its unusual growth habit makes it a sought-after specimen, offering a sculptural element in any collection.
Understanding the Fan Cactus
The fan cactus is a Japanese cultivar of Myrtillocactus geometrizans, native to central Mexico. Unlike its standard columnar counterpart, ‘Fukurokuryuzinboku’ develops a crested, or monstrose, form, with wavy, fan-shaped, or contorted stems instead of a typical straight column.
Its glaucous blue-green stems are 3 to 10 cm thick, characterized by 5 to 8 ribs lined with tubercles, sometimes resembling breast-like shapes. Each areole bears 3 to 9 short spines. While it can reach up to 4.5 meters (14.8 feet) tall and spread up to 5 meters in its natural environment, it remains smaller when cultivated indoors.
Fan Cactus Care Essentials
Light
Fan cacti thrive in bright, indirect light. A south-facing window indoors provides ample light without harsh, direct sun. While they tolerate some direct morning sun, prolonged intense afternoon sun can cause sunburn and damage to the stems. Insufficient light leads to etiolation, where the cactus stretches and becomes pale.
Watering
Overwatering can lead to root rot, so proper watering is important for fan cacti. Use the “soak and dry” method, allowing the soil to dry completely between waterings. During the active growing season (spring through early fall), water deeply every 10 to 14 days. In dormant winter months, the plant needs less water, and the soil should remain almost entirely dry. Check soil moisture about an inch deep before watering; if damp, wait.
Soil and Potting
A well-draining, gritty soil mix prevents waterlogging for fan cacti. A specialized cactus potting mix amended with perlite or coarse sand enhances drainage. Pots must have drainage holes. Repotting is necessary when the cactus outgrows its container or every few years to refresh the soil. When repotting, use a pot only slightly larger to avoid excess moisture retention.
Temperature and Humidity
Fan cacti prefer warm temperatures, 20°C to 30°C (68°F to 86°F) during active growth. They are semi-hardy but should not be exposed to temperatures below -4°C (25°F); nighttime temperatures should not fall below 10°C (50°F). While from arid regions, indoor humidity levels of 30-50% are suitable. Protect them from cold drafts and sudden temperature fluctuations.
Fertilizing
Fan cacti do not require frequent fertilization, as they adapt to nutrient-poor environments. During spring and summer, apply a balanced, diluted cactus-specific fertilizer monthly. Dilute the fertilizer to half or quarter strength to avoid over-fertilization. Withhold fertilizing entirely during fall and winter dormancy.
Propagating Fan Cactus
Propagating a fan cactus is achieved through stem cuttings. The best time for propagation is during the active growing season, in spring or early summer, when temperatures are warm.
To propagate:
Take a cutting from a healthy, mature stem using a clean, sharp knife or sterile shears. Ensure the cutting is at least a few inches long and includes some crested growth.
Allow the cut surface to callus over for two to three weeks. Place the cutting in a dry, well-ventilated area away from direct sunlight during this period.
Once callused, plant the cutting in a pot filled with a well-draining cactus mix.
Do not water immediately. Wait until new growth or roots begin to form, which may take several weeks to a few months.
Keep the cutting warm and dry, between 21°C and 27°C (70°F and 80°F), to encourage rooting.
Once new growth is visible, begin light watering, gradually increasing frequency as the plant matures.
Troubleshooting Common Fan Cactus Issues
Fan cacti are resilient, but issues can arise from improper care.
Overwatering and Underwatering
Overwatering leads to root rot, manifesting as mushy stems. If suspected, remove the cactus, inspect roots, trim rotted portions, and repot in fresh, dry soil. Underwatering causes the cactus to shrivel or appear deflated, indicating a need for thorough watering.
Light Issues
Insufficient light results in etiolation, where the cactus stretches and becomes pale. To correct this, gradually move the plant to a brighter location to prevent sunburn from sudden light changes.
Pests
Mealybugs, small white, cottony insects, can infest the plant. Remove them by gently wiping with a cotton swab dipped in rubbing alcohol. Regular inspection helps identify and address issues.