> plants [...] have relatively narrow conditions

Are you sure about that? Evolution would certainly strive for adaptability... Of course, evolution went through the window when humans started interfering (breeding etc), but still, just looking outside, plants seem to survive (and thrive) in relatively uncontrolled environmental conditions with wild weather swings and varying care (fertilizers, weeding, etc).

On the other hand, I can hardly keep a house plant alive, so there's that.