lack of nitrogen??? someone said that last time, but I've been feeding it somethin thats 24/8/16.. plenty I would think :/
could it be root bound? its in a plastic folgers coffee can and is bout 15 inches tall
ever hear the phrase dirt cheap? nothing i can think of that you can't find in your neighborhood park.
anyway, you don't want pure soil. if you can get your hands on some perlite you should add that (perlite can be found at garden and home improvement stores)