No tropical/lush planets in uncharted systems?

Hello everyone, I've been looking for a nice tropical or even just lush planet to build a base on in an uninhabited system, but for whatever reason after looking through heaps (Green, red and blue stars) I haven't so much as seen one. Are lush planets just incapable of spawning if there aren't any gek/vykeen/korvax, or are they just like really really rare?