Vines in Clay? Wow. I live with pure sand here. Clay is foreign to me. But for a vine,wouldn't alamanda work? And if you go to any garden center, what they carry is USUALLY what will grow in your area.
I didnt know that hibiscus would grow in clay. It grows here in sand great. But it isn't for a fence cover anyway. BUT if you go to a garden center like Home Depot or Lowes or some big name, they will carry what will grow in your area ,USUALLY.
At like mothers day, we get hydrangas here,and they dont last past 1 month,if that!
That is for a special time only. So, if you see a lot of a certain vine in these stores. Chances are,you dont have to ask them,'will this grow here'.Because they give you a year warranty to bring it back if it dies,they do here at least. And if it is in that center, they want you to come back and buy more!! So they want what you buy to live. My $.02.