Hi, you don't need to do anything with it, it only grows to about 1 or 2 metres height and spread, and they're fairly short lived, so you should take cuttings regularly, to replace if it decides that this year is its last, Derek.

I may sound a little amateurish here but, could you tell me how to take cuttings from it please?
Thanks
Mark

You can cut it back about half way in spring though if it gets bigger than you want.

Hi Mark, it's too late now or this year, cuttings of this should be taken in early summer.
Cuttings should be taken from non flowering shoots, app 4-6" long, strip of the lower leaves, leaving about 2 leaves at the top, place about 6 cuttings around the edge of a 4" pot filled with well draining gritty compost, water, and cover with an opaque plastic bag, held in place with an elastic band, {you can use crossed wire hoops to keep the plastic bag off the tops of the cuttings} place them in a bright place, but not direct sunlight, check periodically that they're still moist, they should be rooted in 3 to 4 weeks, when you see roots showing through the bottom of the pot, pot them into individual pots, I use 3 1/2" pots for this, into either multi purpose compost, or john innes no1, grow them on for a few weeks, then plant out in their flowering positions, forgot to mention that the cuttings should be buried about 2/3 of their length around the edge of the pot. Derek.