The Old Lady Cactus or Old Lady Pincushion, like Mammillaria hahniana is also called, is native to Mexico. It is a globular growing cactus and can make it up to ten centimeters in height and diameter.
Mammillaria hahniana plant care
Full to partial sun locations with at least three hours of sunlight daily are perfect.
Oversummering can be done in a spot in the garden or on the balcony, protected from cold autumnal rain.
As substrate I use a semi-mineral mixture of peat-free potting soil, bird sand and pumice gravel.
A standard cactus soil mixed up with clay granules is also suitable.
Mammillaria hahniana is adapted to survive in dry regions. Therefore, its soil must be allowed to dry out between waterings.
In summer it can be deep waterd. Give as much water until the root ball is soaked with it.
During the winter, less water is needed and only watered sparingly. The root ball should now kept mostly dry.
If the Old Lady Cactus shall bloom it is good if it is overwintered cool, at about 41 to 50 °F.