We have 2 standard Red Robins in our front garden and about 2 months ago we noticed one was dropping its leaves. We came home from holiday a couple of days ago and both are absolutely full of blossom (never seen them like it before), although the one has now lost about 50% of its leaves. Has anyone any idea what may be causing the leaf loss and any idea if it will recover?
I think what may have happened to your Photinia's is that while you was away on holiday your shrubs may have been become rather dry or dryer than usual, quite often plants under stress will often produce an abundance of seed to ensure their survival, or at least their offsprings survival.
The loss of leaves, I think bears this out.
Give them plenty of water now that your back and I hope that you will find that they will return to normal. Good Luck Tbird+