We have two trees in our back garden that I am fairly sure are Sorbus aria Lutescens. They are about 12 years old and have reached a height of approx. 20 feet.
They have been planted on the boundary of our garden and very close to a tall, dense hedge of very mature trees, which we trim when they start encroaching onto our garden. Because of this hedge, our Sorbus aria trees have all their branches growing out over our garden and nothing on the other side that faces the hedge.
In order to give the trees a symetrical shape and to reduce their height and width, I would like to prune them. Ideally this would be into a small round or oval shape, but I am unsure how and when to do this. Also, the trees rarely flower and produce berries. They did so last year but not this. Could it be the effect of the trees behind them?
Thank you for reading this far and I hope someone has some suggestions for me.