I am ready to attempt a topiary. I have my wire angels, now I need a vine. It has to be hardy to zone 3 and grow in the shade. I always planned to use the wild vines that grow in my woods but a friend suggested I try a smaller leafed one. Any suggestions?!? Can I use one of the ground cover vines I have growing? It blooms,tiny blue flowers, but I cannot find the name of it at the moment.