My outdoor ones are just stuck in the regular ground we have. Not very good for them as it is a lot of clay. But they are doing fine so I'm not going to mess with them. Also, they are in full blown sun and they have been fine with that too. If it ain't broke......
But the semps I have in containers outside are in Promix mixed with chicken grit. And chicken grit on top of the soil. I have no idea what soil mix I will use when I replant them to someplace more permanent.
