Question
ARE DAHLIAS PERENNIALS  

Answer
Hi Elizabeth,
Thanx for your questions.  Dahlias originally hail from the mountains of Mexico and are from frost-free environments.  They are perennial in frost-free areas or in areas where the ground does not freeze.  In the north, they can be used as annuals or the large tubers can be dug up (lifted) and stored in a cool but not freezing basement until Spring.  I hope this helps.
Tom