i had a green mum plant, it was growing pretty well, then it just died without reproducing.
from what i have observed, most mums don't produce seeds. and i thought that they will always regenerate, but this one didn't.
I've always seen a small baby plant grow from the base of the main plant, and shortly thereafter the main plant dies. Then the baby plant takes over and so on..
Chrysanthemums (mums) reproduce by seed in nature. Man-made hybrids may not produce seed. Mums are almost always commercially propagated by cuttings.