Notocactus schlosseri is a captivating cactus species native to Uruguay, known for its distinct appearance and relatively straightforward care requirements. Its unique features and vibrant blooms make it an appealing choice for both novice and experienced plant enthusiasts.
Identifying Notocactus schlosseri
Notocactus schlosseri typically grows into a globular to short cylindrical shape, reaching up to 8 inches (20 cm) tall and 5 inches (12 cm) in diameter. Young plants are more spherical. The green stem features around 22 prominent, sometimes subtly spiraling, ribs.
Small, woolly areoles, initially white then gray, space along these ribs. Dense, short spines, typically yellowish-brown to reddish, emerge from the areoles. The plant produces vibrant, lemon-yellow, bell-shaped flowers, 1.8 to 2 inches (4.5 to 5 cm) in diameter, usually blooming in spring and summer from the cactus’s apex. These flowers often have contrasting dark red stigmas.
Notocactus schlosseri Care
Light Requirements
Notocactus schlosseri thrives in bright, indirect sunlight or partial shade, benefiting from morning sun. It tolerates some direct sun but avoids intense afternoon sun, which can cause sunburn. Indoors, a south-facing window provides sufficient light. A concave or slightly indented center indicates adequate light, while a flat top suggests insufficient lighting.
Watering
Water Notocactus schlosseri more frequently during its active growing period in spring and summer. During warmer months, water consistently as soon as the soil dries, potentially weekly in hot conditions. Reduce or suspend watering entirely in winter to prevent root rot, as the plant is sensitive to moisture in cold conditions. Ensure water drains completely, and the soil dries within 3 to 5 days after watering.
Soil and Potting
A well-draining, gritty soil mix is essential for Notocactus schlosseri to prevent root rot. A suitable mix includes 50% cactus/succulent soil, 25% pumice, and 25% smaller orchid bark chips. This cactus has finer roots and benefits from slightly more compost. Pots must have drainage holes.
Temperature and Humidity
Notocactus schlosseri is cold hardy, tolerating temperatures as low as 20°F (-7°C) if kept dry. It prefers milder temperatures, ideally above 40°F (4.4°C) at night for optimal health and blooming. Avoid sudden temperature changes, which can shock the plant. Good air circulation is beneficial, though specific humidity requirements are not strict.
Fertilizing
During the growing season (spring through summer), fertilize Notocactus schlosseri with a balanced, diluted cactus-specific fertilizer. Apply at half strength, once or twice in spring and then with every watering during summer, to encourage good blooms. Avoid fertilizing in winter when the plant is dormant.
Repotting
Repot Notocactus schlosseri every two to three years, ideally during its active growing seasons in spring or summer. Choose a pot only slightly larger than the previous one. After repotting, wait a few days before watering to allow any root damage to heal and prevent rot.
Propagating Notocactus schlosseri
Notocactus schlosseri can be propagated from seeds or by separating offsets (pups) from the base of the mature plant. The growing season is the best time for propagation. For seeds, collect them from ripened fruit and sow in a well-draining soil mix with a thin sand layer.
When propagating from offsets, allow the removed pups to callus (dry out) for a few days before planting in a gritty, well-draining soil mix. This prevents rot. Provide warmth and indirect light to encourage root development. Once rooted, care for new plants like mature specimens.
Common Problems and Solutions
Overwatering is a common issue for Notocactus schlosseri, causing mushy spots, rot, and root loss, especially in cold, wet conditions. If soil remains damp for more than a few days, it indicates poor drainage, requiring more grit or repotting. Underwatering can cause the plant to shrivel; a small amount of water during warmer periods can help it plump up.
Notocactus schlosseri can attract pests like mealybugs and spider mites. Regular inspection aids early detection. Insecticidal soaps or horticultural oils are effective for light infestations; systemic treatments may be needed for severe cases. Lack of flowering stems from insufficient light or improper dormancy. Ensure adequate bright light and a cool, dry winter dormancy to encourage blooming.