In zone 5, probably not as your season usually isn't long enough. Normally perennials in your zone would be started much earlier indoors (January). But you might luck out if the weather cooperates so it is still well worth doing and give you even greater performance next year.

Aubrieta discussion on Perennials forum

thanks so much! Now I know not to expect the flowers and won't be disappointed. Hopefully they'll grow enough to plant out this spring and flower nicely next year!