google: rejuvenation pruning of flowering shrubs ... and read a few links.. until you find one that strikes your muse .. it never fails to amaze me.. how variations on a theme.. can be so divergent ... in other words.. how many poor authors there are ...

you remove the largest 1/3 of the branches.. as close to the ground as you can ..

NEVER ... remove 1/3 of a branch ...

what happens.. is that you will get 3 to 5 new sprouts at height.. and when they get long.. they fall to the ground.. gravity and all ...

if you gogle pix of W .. you will find.. that the most glorious.. look like exploding fireworks... and that is because... they have straight limbs from the center ...

see link .. and just note the various forms.. and how properly pruned ones are well proportioned and rather tame... as compared to those.. improperly pruned.. and left to heap upon them selves ... which is not a bad form.. if you have 50 sq feet of space for such a beast ...

its really all about your goal.. or vision for the plant...

now... i would not go hog wild.. reducing leaf mass.. on a recent transplant... your is one year in the ground.. and is PROBABLY WELL ESTABLISHED... but lets err on the side of it needing to continue to grow a good root mass .. and not get carried away.. by cutting off half of the energy makers.. the leaves ..

as i always like to say ... i can always take off more in the fall [after dormancy.. and this years work is done] .. or next year.. i cant glue or staple them back on ...

ken

Here is a link that might be useful: link

Very good advice. Not my question, but very informative. Thanks Ken