My hanging plants

I bought a couple of hanging petunias when we first moved to South Carolina. I was a little nervous about any kind of plants because I've never had a green thumb. I'm so proud to be able to say that my petunias are still alive...
And not only are they still alive, but they are thriving! They are still blooming and beautiful.
Anyone know what you do with plants in the winter? Should I just throw them out and get new ones next year?