My yucca has finished flowering, and now there are what looks like seed pods on the stalks. Should I let them go to seed?
I wouldn’t. Most those seeds rarely germinate, and producing those seeds, along with having just produced their spectacular flowers, really takes a lot out of the yucca. I suggest removing the flower stalk as soon as it finishes flowering, and let the yucca put the rest of its energy into being a better plant.