Hi, I'm new to the forum (new to posting , anyway) but I just bought an African milk tree that's about 16" tall. It's in maybe a 4" pot and I was wondering what size pot to transfer it to. Can they stay in a small pot in general regardless of size? I have another one that's maybe 6" tall that's grown at least 3" since I got it at the end of fall. They seem like super-fast growers, I want to make sure I put them in pots big enough to support the roots... or maybe not if they have really compact root systems.