I enquired about this last year but I didn't retain the reply (sorry!)
I have looked up in my gardening books about pruning Philadelphus but it says after flowering. My plant was new in Spring last year and has not flowered yet. It is in a raised bed and has grown about 8 leggy branches (some over 6') and they are leaning over somewhat. As my garden is quite tiny it's height is beginning to overpower the border. Can I reduce it's height?
I will try to post a pic to give better idea. Hope it works!