The gemara in Nedarim 59 (among many other places) discusses the concept of shmita produce and plants grown from them retaining their status when the original "seed" isn't destroyed when planted. In discussing this point, it brings down that the kedusha of shmita is caused by the land itself. This would imply that objects "not grown in the land itself" would not have shmita upon them even IF they were "grown in Israel."
Nominally, this would exclude things like hydroponics or pot grown vegetables.
However, we also have a halacha that a large enough vessel is considered equivalent to the ground itself, as it comprises an immovable object. As such, a date tree (say) grown in a sufficiently large planter WOULD, in fact, have all the requirements of shmita.
Given that there are concerns in general with hydroponics and their status re: making a bracha, would the "large container" concern still apply to render such produce kodesh lishmita?
