N poeticus, Pheasant eye, blooms very late. Another possibility is that the bulbs have been weakened by the foliage having been mown off too soon over previous seasons.

It is still quite early for many daffs in zone 8. They are just starting to get going in my zone 8/9 location - in fact, the local daffodil festival is not schedule yet for a couple more weeks.

Transplanting does not have to wait until the foliage fades - it can certainly be done now, particularly if these are not blooming bulbs (although that's not necessarily a deterrant either).

Thank you both for your replies. I don't think I've ever grown any varieties that bloom this late. I think I'll start digging and transplanting tomorrow.