Ferocactus macrodiscus is a captivating barrel cactus, celebrated for its distinct form and vibrant features. Its flattened, disc-like shape makes it a compelling addition to various plant collections.
Understanding Ferocactus Macrodiscus
Ferocactus macrodiscus is a medium-sized barrel cactus with a disc-shaped stem, reaching up to 4 inches (10 cm) tall and 18 inches (45 cm) in diameter. Its epidermis exhibits a blue-green hue. The cactus features 13 to 35 pronounced ribs.
This species displays curved, yellow or red spines, with 6 to 8 radial spines and 1 to 4 central spines per areole. The central spines can be up to 1.4 inches (3.5 cm) long. Funnel-shaped flowers measure up to 2 inches (5 cm) long and 1.6 inches (4 cm) in diameter, appearing in shades of white with bright purple or pink stripes. Blooming occurs from spring to summer, between April and July in its natural habitat.
Native to Mexico, Ferocactus macrodiscus is found in states such as Guanajuato, Oaxaca, Querétaro, and San Luis Potosí. It thrives in very dry areas within grasslands and oak forests, at elevations ranging from 2,300 to 2,600 meters above sea level. During periods of drought, the plant can sink into the ground, making it difficult to locate until rains prompt it to swell and prepare for blooming.
Growing and Caring for Ferocactus Macrodiscus
Providing sufficient light is important for Ferocactus macrodiscus, as it thrives in full sun. It benefits from at least 6 hours of direct sunlight daily. When grown indoors, a south-facing window offers the best light exposure.
Watering should be infrequent and thorough, allowing the soil to dry completely between applications. Overwatering is a common issue for cacti, so ensuring the plant does not sit in wet soil is important. During the winter, when the plant is dormant, watering should be significantly reduced or ceased entirely.
The ideal soil for Ferocactus macrodiscus is a well-draining mix that mimics its natural arid environment. A suitable blend can include a commercial cactus mix amended with perlite, pumice, or grit to enhance drainage. The soil pH should be around 6.
Ferocactus macrodiscus tolerates heat well and prefers temperatures above 40°F (4.4°C). High humidity, especially during its winter dormancy, can be problematic. Repotting is infrequent, only necessary when the plant becomes root-bound or the soil needs refreshing, typically every other year in spring. When repotting, select a pot only slightly larger than the current one to prevent overwatering.
Fertilization is not a frequent requirement for this cactus. If chosen, a low-nitrogen, potassium and phosphorus-rich cactus fertilizer can be applied at half-strength once a month during its active growing season in spring and summer. Avoid fertilizing during the dormant winter period.
Common Issues and Solutions
Overwatering is a significant concern for Ferocactus macrodiscus, often leading to root rot, indicated by soft, mushy spots on the stem. If detected, reduce watering immediately and allow the soil to dry completely. In severe cases, repotting into fresh, dry soil might be necessary.
Underwatering can manifest as a shriveling appearance. While this cactus is drought-tolerant, prolonged lack of water can cause dehydration. A thorough watering can help rehydrate the plant once signs of shriveling are observed.
Ferocactus macrodiscus can occasionally be affected by mealybugs or scale. These pests can be treated with insecticidal soap or neem oil. Regularly cleaning the plant with a painter’s brush can help remove dust that might harbor pests.
A lack of flowering can stem from insufficient light exposure or inadequate nutrients. Ensuring the plant receives ample direct sunlight and light fertilization during the growing season can encourage blooming.
Etiolation, characterized by a stretched or elongated appearance, indicates insufficient light. This condition is irreversible for the affected growth. To prevent further etiolation, move the plant to a location with more intense and direct sunlight.
Propagating Ferocactus Macrodiscus
Seed propagation is the primary method for reproducing Ferocactus macrodiscus, as offsets or pups are rare for this species. Starting from seed allows for the creation of new plants, which can be a slow but rewarding process.
To propagate from seed, use a well-draining cactus potting mix. Sow the small seeds on the surface, gently pressing them into the soil without burying them deeply. Mist the soil to moisten it, then cover the pot with plastic wrap to create a humid environment conducive to germination.
Place the pot in bright, indirect light and maintain a consistent temperature between 70-80°F (21-27°C). Germination can take several weeks to a few months. Once seedlings sprout, remove the plastic wrap and continue to provide bright, indirect light, gradually acclimating them to more direct sun as they mature.