Gymnocalycium stellatum is a small, slow-growing cactus species native to the semi-arid regions of Argentina. It features a flattened, spherical growth form that can reach up to 10 cm in diameter, displaying colors ranging from dark grayish-brown to olive green, adorned with 7 to 11 ribs, each bearing clusters of straight to slightly curved spines. During late spring, it produces creamy-white flowers with a subtle red throat.
Native to: Gymnocalycium stellatum is indigenous to Argentina's semi-arid regions, where it thrives in well-drained soils and receives ample sunlight.
Water: During the growing season (spring and summer), water Gymnocalycium stellatum thoroughly when the soil has completely dried out. In the dormant period (autumn and winter), reduce watering frequency, allowing the soil to remain dry for extended periods to prevent root rot.
Light: This cactus prefers bright, indirect sunlight and can tolerate some direct sun. However, in indoor settings, providing 4-6 hours of bright, indirect light daily is ideal. Supplementing with grow lights can be beneficial, especially during shorter days..
Humidity: Gymnocalycium stellatum thrives in low humidity environments, typically between 30-50%. Maintaining minimal humidity levels is crucial to prevent potential issues like rot.
Temperature: Maintain indoor temperatures between 18°C to 24°C for optimal growth. While the cactus can tolerate brief drops to 10°C, it is sensitive to frost and should be protected from cold drafts and sudden temperature changes.