Gymnocactus

Family. Cactaceae.

Origin. Mexico.

Description. Gymnocactus is a small cactus with a spherical bluish-green stem up to 15 cm high and up to 5 cm in diameter, which takes on a cylindrical shape with age. The apex of the stem is densely pubescent. The spines are light in color, long – up to 3 cm, slightly bent or straight. The central spines are darker - brown or black. The flowers are funnel-shaped, 3 - 4 cm in diameter, pink-violet, yellow, purple, white or greenish-white, appearing at the top of the stem.

Height. Up to 15 cm.

Home care

Temperature

Heat-loving species. The minimum temperature for keeping gymnocactus in winter should not be lower than 5°C if the plants are kept in almost dry soil.

Lighting

Bright sunlight with light shading on particularly hot summer days. Lack of lighting causes the stem to stretch.

Care

Gymnocactus is very easy to grow and suitable for beginners, but develops very slowly. This cactus is a xerophyte - a plant adapted to dry soil and very sensitive to excess watering when kept in a poorly ventilated room, especially after the first flowering. Often grown on rootstocks.

Substrate

Grows in mineral sandy cactus soil with very good drainage. 

Feeding

Feed once during the growing season with a cactus and succulent fertilizer (high potassium, low nitrogen) at half strength. This species thrives in nutrient-poor soils.

Flowering time

Spring – March-April.

Air humidity

Suitable for rooms with good air movement without cold drafts. In winter, the air in such a room should be dry.

Soil moisture

Gymnocactus is watered infrequently, allowing the soil to dry out between waterings. In winter or at night temperatures below 10 °C, watering is reduced so that the soil ball is almost dry. At this time, adult specimens easily rot and die from excessive watering.

Transplant

Once every 2 - 3 years in the spring.

Reproduction

Most often propagated by seeds, as this cactus rarely forms lateral branches that could be used for propagation. Seeds are sown in loose, well-drained sandy soil in the spring. The crops are sprinkled with a thin layer of sand on top. Cover the pots with a plastic cap or bag for 1-2 weeks to maintain the humidity level. After 2 weeks, remove the cap and spray the seedlings 1-2 times a day for the next 2 weeks, during which time the seeds should germinate. By grafting.

Pests and diseases

Almost all problems arise from waterlogging and poor ventilation, especially in autumn and winter. This cactus has a taproot system that rots easily. Excessive fertilizers lead to rapid growth, but the plants become more susceptible to fungal diseases.

Pests that can attack gymnocactus include spider mites, mealybugs, thrips and aphids.