Hello, i prune one similar size to yours each may, i use shears and lightly clip all the way over it, going in aprox two inches, also rather than be really severe with the whole plant, i will cut down on selected branches to encourage new growth further down, and will do this on other parts each year, going back to useing the shears, it will look a little sad but soon picks up again, dont forget to feed and water, julien.

Thanks julien - will certainly take your advice. Alice

Thank you all - I've been wondering the same thing , so now I will use some of it for cut flowers!