There all in at least 10 gallons of good potting soil with lots of drainage,you just can't see it in some pic's.
What I did was cut the bottom off the 2.5 gallon pot they started in and placed it on top off about 10 more gallons of potting soil(just the 2 somango's)
The other 2 are in those regular pots, those are clones.
Also the older the plant the more soil they have(look at the big somango,it's had a full growing season so far,planted april 20th...4-20) romulan and B.M. planted June 1.