Plant in a porous cactus mix with adequate drainage. Gymnocalycium species, as a rule, do not care for hot, stuffy locations, instead preferring cool, airy, shady areas. Water thoroughly when dry to the touch.
How to Grow and Care
Some Gymnocalyciums are shade-seeking in the wild, among shrubs or grasses, while others grow completely exposed. Some will therefore need a light shading from the sun in the hottest months, but to overdo this will result in loss of plant.
The balance of the potting medium should be sufficient to allow good drainage, so that the plants do not sit in soggy soil for more than a day or two after watering. Watering in the summer months, while the plants are growing well can be frequent (bi weekly for small plants in small pots), but always allowing the compost nearly to dry out before watering.