A mature bush should have thick enough canes to be a bush. Mine is 5 years old and has mostly thicker canes that don't bend too much until they get 7-8 feet long. Even then they don't bend so far as to reach or lay on the ground.

James, my AS is an own-root plant in its second year in Zone 5 Illinois. Last winter we had -22F temps in January, so it started out spring with having to be pruned to about 1' due to winterkill. However, it recovered nicely and is now reaching upwards towards the 2nd story bedroom window. I have found that AS needs a trellis for support because the canes are very lax and not very stiff...probably because mine is own-root rather than grafted, perhaps.

-terry

Terry
Yours should get thicker more upright canes as it matures.
Many own roots plants produce lax canes until they mature. A couple of my rooted Autumn Sunset cuttings have produced very long canes this first year. My two five year old plants in the ground produce very thick upright canes.

Thanks for the replies. I may just start it as a climber and move it a few years later. How vigorous is AS? Would it be a royal pain to move a 5 year old plant?

I think AS would make an awesome shrub.
The canes on mine are thick and my guess is it would top out at 6-8 feet in my zone.
Mine is currently being employed eating a cyclone fence so I love the robust growth.
Beautiful flowers and a great fragrance to boot.
Better than Westerland in my opinion.

If you're going to move it in a few years grow it in a really large pot now.

Good suggestion Karl, I'll try that.