So first, is it possible to grow your own Fly Agaric mushroom? Well, technically, yes, would you be able to though, very likely the answer to that would be no. Amanita Muscaria mushrooms are what is considered a symbiotic plant, meaning that it forms a mutual relationship with another organism that allows it to grow. The most common tree you will find them under is the birch tree. You would have to be very lucky to actually plant your own next to a birch tree for example and have them bond together, and have the mushroom grow and become edible. I would just stick to buying them online if I were you. I buy my fly agaric or amanita muscaria mushrooms from Herbal Fire Botanicals . They seem to have the best quality, as well as great customer support and quick shipping.
Amanita Muscaria trip description, dosage, and preperation