I have a wide double row beech hedge. How and when can I cut it back severely ? One row grows towards the front, and the other to the back. The middle of the hedge is like an empty “tunnel”.If I cut back one side I will leave the trees on that side with hardly any leaves. Would there be a danger that this may kill the row, or should I remove one row altogether ? It has become difficult to trim as it’s about 6 ft.6in. tall and about 4 ft.6in. wide in places.
You could remove one row entirely, although it might be slow to leaf up on the bare side, or you could ‘breast’ both sides, the sunny side one year and the shady side two years later, cutting back hard to narrow it and allowing re-growth. This can be done in late winter.