I have one of these plants growing against a shaded garage wall. It was only planted last year and wasn't very mature when planted. It hasn't flowered this year but in fairness I didn't expect it to but it has put on an amazing amount of growth.
Looking at it today it has 3 main healthy branches which are only about 18-24 inches from the garage roof. I was wondering if I cut all the branches back a bit would this encourage it to grow bushier? I don't really want to jeopardise any potential flowers for next year though!