If you live in a cold climate in the winter you don't have to do that. but if you live where it does not freeze in the winter you will have to do that. People living in Florida would have to do that. But in NE PA last year we had 22 days under zero and a very cold bitter snow filled winter. Good luck with your bulbs....where ever answer is best for you remember to add bone meal around those bulbs after flowering or in the new hole when replanting.