For six years, Mammillaria zeilmanniana is the most active of my cacti when it comes to producing flowers. It shows off 2 cm wide pinkish-purple flowers all throughout the year even when I seldom tend to it. This cactus is also commonly known as the Rose Pincushion Cactus. Coincidentally, I bought it from Rose (a succulent-dealer) last June 2005.
The body of this cactus is glossy green and full of tubercles. You need to take a closer look because the spines cover the whole plant. The white ones are the radial spines, which are about 15 or more found on each tubercle. (Their main function is to collect moisture.) Then, there are also the four reddish-brown central spines on each tubercle — 3 straight and 1 hook. (These fend off little birds that covet its whitish-green fruits and humans.) I always watch out for the hooks when I tend to this cactus but I guess I just couldn’t avoid them.
I’ve heard that in its natural habitat, this cactus rarely branches out. However, it is not in the case here in my garden; from a single plant, it initially produced a cluster of offsets that became clumps later on. I say this plant is very generous that I need to re-pot it every two years.
The offsets thrive well in pots with good cactus soil (I just mix sand, loam soil and rice hulls). I put them in an open area where they get full sun exposure and lots of air. During the dry season, watering is only needed when the soil is hard to the touch. However during the wet season, I refrain to give it water for this plant is prone to rot. Overall, I like this cactus because of its purple flowers and that it is easy to care for.