Pack Size: 20, 100, 300
Year: 2026
Accepted Scientific Name: Gymnocalycium pflanzii (Vaupel) Werderm.
Origin and Habitat:
Gymnocalycium pflanzii is an attractive cactus species native to South America, occurring in Bolivia, Paraguay, and northwestern Argentina. It inhabits seasonally dry subtropical forests, thorn scrublands, rocky hillsides, and open grasslands, often growing among low shrubs and sparse vegetation. Plants are found in mineral-rich, well-drained soils, sometimes partially embedded in the ground or sheltered beneath surrounding vegetation. These environments experience warm summers, cooler winters, and seasonal rainfall followed by extended dry periods. The species is adapted to strong but filtered sunlight and variable moisture conditions. Its broad natural distribution has produced considerable variation in body colour, spination, and flower characteristics.
Description:
Gymnocalycium pflanzii is a slow-growing, predominantly solitary cactus characterized by its globular to slightly flattened shape, becoming more rounded or elongated with maturity. Mature plants typically reach approximately 4–8" in diameter and 3–6" tall, occasionally growing larger under favourable conditions. The body displays dark green to grey-green colouring, sometimes developing bronze or purplish tones under strong sunlight. It features approximately 8–15 broad, rounded ribs divided into prominent chin-like tubercles. Each areole produces several strong, curved spines, initially reddish-brown to dark brown, gradually fading to grey with age. Mature specimens produce attractive, funnel-shaped flowers approximately 1.5–2" across, displaying creamy white to pale pink petals with distinctive deep rose-red to purplish-pink throats. Flowers emerge near the crown during spring and summer, followed by rounded fruits containing numerous small seeds. Its impressive spination, prominent rib structure, and contrasting flower colours make it a desirable addition to cactus collections.
Cultivation:
Zone: 9–11; protect from prolonged frost and excessive winter moisture.
Temperature: Optimal growth at 18–30 °C. Maintain winter temperatures above 5 °C for reliable cultivation.
Growth Rate: Slow to moderate, gradually developing a broad, globular body with prominent ribs and increasingly strong spination.
Soil: A highly mineral, fast-draining cactus mixture containing pumice, fine gravel, and a moderate proportion of organic matter. Excellent drainage is essential for healthy root development.
Watering: Water thoroughly during active growth, allowing the growing medium to dry between waterings. Reduce watering significantly during autumn and keep mostly dry during winter dormancy.
Fertilizing: Apply a diluted, low-nitrogen cactus fertilizer every 2–3 weeks during active growth. Discontinue feeding during winter.
Light: Bright light to partial sun. Gentle morning sunlight encourages compact growth, strong spination, and healthy flowering. Protect from intense afternoon sunlight during extreme heat, particularly for young plants.
Pests and Diseases: Susceptible to mealybugs, root mealybugs, spider mites, scale insects, and root rot associated with excessive moisture or poorly draining growing media.
Germination Info:
Temperature: 27 °C.
Surface Sown: Yes. Sow seeds on the surface of a fine, sterilized cactus growing medium and press lightly into place without burying deeply.
Germination Time: Approximately 7–28 days under favourable conditions, although some seeds may require longer.
Moisture: Maintain consistent surface moisture and high humidity during germination, avoiding waterlogged conditions.
Light: Bright, indirect light. Avoid direct sunlight on covered seed trays.
After Germination: Gradually increase ventilation as seedlings establish. Maintain moderate moisture until young plants develop stronger root systems and begin producing characteristic ribs and spines.
