I'm new to Arizona and we planted our plant in the spring. I am going to start some in the greenhouse this winter so they will be ready to be planted in the spring. So probably in the spring, not really sure though. You could look it up on the internet though.
I have my plant just planted in the dirt with some potting soil mixed in with it and I fertilized all my plants with miracle gro. But they do have cactus potting soil but I only use that if I put them in a pot. And use cactus fertilizer.