Mammillaria hahniana, also known by its common name ‘Old Lady Cactus’, is a popular powder puff type cactus that is sun-loving and easy to grow. The plant, which belongs to the Cactaceae family, is particularly attractive with its lone spherical stems and flowers in hues of red-purple. It can grow up to approximately 4 in. (10cm) tall and 8in. (20cm) wide.
For the most part, the Mammillaria hahniana is known as an outdoor plant but can be grown indoors too. The Mammillaria hahniana thrives in dry, hot conditions with very little water. As such, the plant does better in an outdoor environment where it lavishes in the sun. Even though the Mammillaria hahniana loves the outdoors, it does not mean that it cannot be grown successfully indoors. The Mammillaria hahniana can grow quite well indoors in a pot if it is placed in a very sunny area and is not overwatered.