Like any other cactus. They like a coarse gritty soil, lots of sunshine and need keeping dry in winter. They make large plants eventually though so if you grow them successfully you will soon need a frost proof greenhouse. Be careful handling them because the little hairs that grow in tufts (glochids) where the spines emerge are like tiny fish hooks and will stick in your flesh if you touch them which makes repotting them lots of fun! Elastoplast or sellotape is the best way of lifting them out if you get any. They also grow on the fruit so it needs handling carefully until they have been removed.