I'm not sure, but I suspect it is one who rises from the compost heap each election to vote Democrat and then resumes the nitrogen cycle again shortly thereafter.
It's code used among leftists who ironically consider themselves top of the socialist heap. In this instance, it means buying organic arugula at Whole Foods.
Then, there are the other coded uses. Marijuana growers are cultivated Democrats, whether that's a full-blown illegal operation on national park land or a single plant in some hapless stoner student's foil-lined and grow-lighted closet.
It gets ugly when referring to Chicago or to ethnic minorities, however. In this instance it's referring to Democrats who are shot, shovelled and shut up, then plowed under to hide the bodies.
Funny how Democrats wrap the language around their hypersensitive little pinkies to avoid coming across as what they are, isn't it?