Posted: 24/02/2015 at 14:09
Charlotte, it benefits by being cut back hard, albeit at the expense of,those flowers. I prune back annually to 15 to 30 cm from the base. I also pinch back new shoots a couple of times during the growing season ...does two things. Firstly makes it more dense. Secondly it produces better colour. if you want a compromise you can cut back alternate shoots and leave others intact.
it grows fast from cutting back hard......will grow at least 2 metres in one season.