La Mammillaria hahniana It is one of the most common, but at the same time most beautiful of the genre. Despite its appearance, do not be fooled as its spines are rather harmless. In addition, its little flowers sprout every spring effortlessly, just with a little water and being exposed to sunlight.
It is a very interesting cactus plant, both to start the collection and to make it grow, since it is a wonder to have it.
Mammillaria hahniana is the scientific name of a cactus plant endemic to Guanajuato, Querétato and Tamaulipas in Mexico which was described by Erich Werdermann and published in Monatsschrift of the Deutschen Kakteen-Gesellschaft in 1929. It is popularly called by the name Old Biznaga de la Sierra de Jalpan.
It is characterized by growing up to 9 centimeters in height and up to 10 cm in diameter.. Their areolas are conical in shape; From them sprout 20 to 30 radial spines 1,5cm long that are like white hairs, and 1 to 4 central spines which are shorter and whitish. The flowers, which appear in spring, are deep pink and measure about 2cm in diameter. The fruit measures about 7mm, and inside we will find very small brown seeds.
If we talk about its cultivation and maintenance, it is a very grateful cactus. In fact, It is only important to remember to put it in a sunny exhibition, and to water it about 2 times a week in summer and every 15-20 days the rest of the year.. Of course, to get it to produce more flowers, it will be very necessary to fertilize it during the spring and summer with a liquid fertilizer for cacti or with Nitrophoska Blue.
It can be grown outdoors all year long if the temperature does not drop below -2ºC., but yes, you have to protect it from hail, especially if it is the first winter you spend outside.