I too am thinking of spiralling some of my Cedrus, but I think Arborvitae (aka Thuja occidentalis) my be too loose and not full enough to give it proper shape. I think you need a hedge plant that is more compact than some of the more common Arborvitaes. Perhaps yours is a very compact growing variety. I saw a show once on PBS about 4 years ago about a self taught topiary artist who used nothing but a 16inch chainsaw. He would literally carve out his shapes, not unlike ice sculptures, in a matter of minutes. Granted the more he carved out the more the exposed dead wood showed, but it all grows back.
He was not some hack that had nothing better to do. His designs were displayed in a garden of about 4 or 5 acres, and he has won awards for his topiaries. Not just small ones, but big 10 foot and more specimens. Plus PBS showed him on TV, so he must have a good reputation.
He even demonstrated a spiral topiary in front of the camera, and used his chainsaw to shape it in about 2 minutes.
Maybe there is some inspiration there for you. good luck. If you do proceed. Let us know how it turns out.
I think this is a new forum on the Garden Web. Not much action here.
Lori, If you have a tall plant you want to prune into a spiral try taking two strips of ribbon and tie them to the top of the plant. Spiral the ribbon down and around the plant and tie off at the bottom. This will give your a fixed prunning guide. Just trim outside the ribbon path or train the growth outside the path towards the inside with stiff wire. Sorta like bonsia training.
Hope this helps
Mark Ritchie