Yes, you can, although it will look very woody and twiggy afterwards. So it's best to wait until spring or you'll have to look at an ugly plant til the end of summer. You can trim back a few of the longer shoots now, but try to leave some leaves on the bush. Use the trimmings as cuttings and grow some extra plants! The plant may take a few years to flower, after cutting back.

Thanks Volunteer, this is why it's got so big. There isn't a time of year when it doesn't look good so I just trim off a few shoots. I hate that 'woody' look.

Try taking out a few branches right to their base, every year. Choose different ones each time and that shouldn't cause too much ugliness!

Good Idea!!! Many thanks Volunteer

The time to prune this shrub is immediately after it has flowered, so about the end of May or in June - then you can be quite rigorous if you need to to be, though as Volunteer says, it will look a bit woody for a short time. Prune it now and you'll lose your flowers next year, so give it a light trim if you must, and save the hard cutback for next year.

Thanks Bamboo