My neighbour and I are trying to find a way to build and render my 2.5 storey extension wall, without compromising his 5m tall leylandii trees, which are planted about 70cm from the boundary wall (on his side). There is currently no growth on the “our” side of the bottom half of the trees, due to the shading effects of our existing 1 storey structure. What would happen the trees if they were cut the back to the trunk all the way to the top? If the worst comes to the worst, is it possible to buy and plant mature leylandi and at what cost?
You are probably better off without them and plant some climbers on your wall.
Five or six-metre leylandii can be bought … up to several hundred € each.