Fat plants

Gymnocalycium andreae


to the genus gymnocalycium belong about seventy species of small cactaceae, native to South America; they generally have a globular body, or briefly stretched, and reach 10-15 cm in diameter. Some species tend to shrink, producing some small plants, which develop on the sides of the mother plant. The body of the gymnocalycium is dark, sometimes greyish, or even purple; they have often showy areoles, which carry short, sharp, sometimes curved spines. In spring they produce large white, pink, red or yellow flowers. The gymnocalyciums are very appreciated by the lovers of succulents, for the ease of cultivation, the contained dimensions and also for the abundant blooms.


they are generally grown in a container, since they fear intense cold, in winter it is advisable to grow them at a minimum temperature above 5-8 ° C; some species can withstand temperatures of some degrees below zero, but only if the soil is completely dry. They prefer to receive a few hours of direct sun, but avoiding the sunny positions for too many consecutive hours, they are therefore cultivated in a partially shady place.


from March-April, until September-October, water quite frequently, when the soil is dry, even leaving it dry for 2-3 days before supplying water. Mix every 15-20 days with water from the fertilizer for succulent plants, poor in nitrogen and rich in potassium. During the cold months water only sporadically the specimens that are grown in the apartment or in a heated greenhouse, otherwise avoid watering.


they prefer not too rich and very well drained soils; a good universal soil is used, mixed with equal parts of sand and lapillus or pumice stone. These cacti do not develop very quickly, so they are grown in small containers, and repotted every 2-3 years.


it happens by seed, in spring. Place the seeds on the surface of a prepared soil, mixing peat and sand in equal parts; the substrate must be kept moist until germination; seedlings are kept in a shady place.

Pests and diseases

they fear very much the cochineal, also radical, and the rots due to water stagnation.


During the summer water abundantly, while in the cold months we recommend to let the compost used for cultivation dry completely. Some species produce shoots
laterals that can be detached (in summer), left to dry for about three days and then planted.

Gymnocalycium andreae: The most common species

G. Andreae: Originating in Argentina, it is characterized by a bulbous stem of almost dark color, about 3 cm wide. The central spines are 1 to 3 and white in color, while the radial spines are generally from 6 to 8. The flowers are bright yellow and about 4 centimeters wide.
G. Baldianum: originally from Argentina, it has a trunk 4 or 5 centimeters high, 6 or 7 wide and dark green. The radial spines are 5 while they are 5 or 6 centimeters long, while the central ones are completely absent. The flowers are about 4 centimeters long and red in color.
G. Denudatum: species native to Brazil, with a light and intense green stem. The main characteristic of this plant are the radial spines (the central ones are absent) which are from 6 to 8 and yellow. These thorns, usually curved upwards and 8-10 cm long, appear "similar" to spider legs. Hence the nickname "Cactus spider". The flowers are 6-7 cm long and white or pale pink.
Among the most beautiful species we point out the NIGRUM, named for its typical black spines.