Posted: 04/03/2016 at 15:57
They're pretty tough and will take a fair bit of hacking back without any real problems, but if you want to be cautious, you can take it back a good bit in summer to get on top of it, and give it a feed, water and mulch . You can do the same later on in autumn so that you can re train it where you want it, or do any maintenance to your fence etc. The only drawback is that you'll lose flowers for a while, but the plant will be rejuvenated
They do get quite rampant once they find their feet!