These plants really don't like heavy, hard pruning, being best with a good trim after flowering, other than removing dead wood.

You could take a risk and prune it back the way you want, and see what happens, but be prepared for the fact it might just die. Maybe its time for a replacement anyway, as yours has got so large and unmanageable.

I would replace it too - they grow quite fast. Have you noticed the pig face in the first picture??

I can see a cat with one black ear and a black splodge over one eye. ?

I would let it flower for this year. Wait until late summer, cut it back hard, taking out any dead or crossing stems, just above any new growth. I would take cuttings and preferably overwinter in cool greenhouse or sheltered position in the garden. If the main plant does not produce any regrowth the next year, you should have back-up from some of the rooted cuttings. If the worst happens you can purchase a new plant the following spring in the knowledge that you have tried your best.

Hello,

Thanks for the replies.

I've uploaded another photo, which shows the size of the tree (for reference the fence panels are 6 foot high).

I *did* prune the new growth back after flowering last year, where I could reach it, so waiting another season is only going to make the thing even bigger still. As it is, I can't reach the top branches now to prune them anyway.

There are a few newish stems from the base of the plant (which you can see in the top photo) so if the upper branches don't survive a drastic prune, hopefully the root and those will serve as a good start for regrowth.

What I would really like to know is whether there are specific pruning tips for doing the least damage. For example, how and where to cut (e.g. position relative to lower branches), and when to do it (should I wait till after all risk of frost?) etc.

I'd still like to know whether the withering that happens well below a cut is inevitable or something specific to my technique.

Piers.

It's not specific to your technique, this happens anyway when you cut into old wood. It does sound like your plant might be okay because it has decided (as they sometimes do) to shoot nearer the base as a response to pruning, but any mature branches you partially cut back are likely to die back anyway.

These really should be pruned lightly each year after flowering to prevent them getting too leggy and the advice is generally that they dislike cutting into the old wood. So if you do decide to be drastic it might be best to do half to a third of the stems each year rather than all at once.

I'd start another off in a pot to be on the safe side, and /or take some cuttings as Jimmy suggests.(semi ripe stems in late summer)

I had a look at a couple of university botanical gardens websites and the consensus was that this doesn't particularly like being pruned but does respond to hard pruning (late summer, when flowering is over).