I planted dahlias this summer that I was told were of the annual not perennial types. They have now died (first frost), so I was pulling out the withered, ugly flowers (zinnias, marigolds, etc.). When I yanked out the dahlias I see at least 15 bulbs!!! Should I keep, and if so, how do I store? Or should I just pop them back in the ground? Thanks for any help.