I'd suspect insufficient sun.

In case the deer are getting the buds only you could turn a wire basket over them. Are you in a zone where they receive what winter chill they need?

you could try dividing and replanting with some compost after the foliage dies back. I hear that they're heavy feeders and like frequent replanting.... they're much more work than your average crocus unless you have a perfect spot for them.

Hi everyone! Thanks for responding. They get a lot of sun, but they are competing with this horridly invasive applemint that is taking over the yard. Ugh! Bleech! Maybe it's tired from competing with that, though I've been ripping the applemint away from it when I get a chance. I did fertilize it last fall with worm water, so hopefully that will help. I didn't know they are heavy feeders! FYI I also planted 20 of them at my parents house, and theirs didn't flower in the fall either. And, they are fanatics about weeding as well. Could it be too cold for them? I'm in zone 6A and parents are in same zone, though a bit more north.