A lot of people will have their own preference but to be honest any soil with the right constitution will do. I use just normal compost from my local hardware store. I add a few things to it like perlite, gravel and vermiculite to aid with aeration, drainage and nutrient control. It's a plant at the end of the day. A very resilient one at that. Treat her with care and attention and she will flourish. Less is more is my motto. Better to have not enough than too much of something. Hope this helps