well they do take a little time to settle in but I'd have expected some growth. but if they are still green then they are still alive. are their roots in shade and their leaves in the sun? this tends to be the favoured way to plant them.
are they well watered?

Did you really mean three inches tall?

Hi Stera I read that as 3ft [3'] lets hope that's what was meant.

If you have the extremely sandy soil parts of SC has, did you feed them? If in gumbo clay, did you condition the soil before planting them? You might also want to check the soil pH--if it is very acid, that could also stunt them, Sami.

Hi, if on the other hand you did mean 3 inches, they must have been sold as 'plug plants', in which case did you remove the little net bag around the roots ?, Derek.

Hi, I'm in UK & planted Clematis (Montana) same time as you, mine is over 20ft tall climbing up my house - hoping for Spring flowering. Hope yours starts soon! ?