They don't have to be cut back. Are they coming back from the roots or budding out? With the type that come back from the roots, some people say it's better to not cut them back until the spring as the old growth helps protect the roots.
With the type that bud out, as far as I know, the only reason to cut those back is to keep them in a certain size/shape.
Barb

It seams they are coming back from the root. Once they start blooming I will better know what type they are. As for right now, we are just enjoying them with anticipation!