Got one of these things as a drop but didn't remember exactly where , planted 5/17 or 5/16 with all known likes, RBF, KP, Tropical Garden Gnome, Pixie. So far it has not made it to mature, in fact the status bar is around 3/4th of the way there so it is a very very slow growing plant. As far as needs go I can confirm music, sunshine, and magic, it may get more but to be honest I haven't really paid attention. Worst thing about this seed is it gets Rank 7 pests, fire ants, and that cost 35 energy to get rid of them. Basically as far as I am concerned, unless this plant drops a guaranteed mega at mature harvests they are absolutely worthless energy hogs thanks to the heavy need requirements and rank 7 pests.
Even the Silver Chests in the Shadow Palace have better drops than Morganthe!