Pollarding is the removal of all branches to leave just the main trunk. This work is not normally done to healthy trees as it causes large wounds which will jeopardise the long term future of the tree. It is only recommended as a last resort for mature trees to retain a tree if it has server decay/die back.

 

Once a tree has been pollarded it will need regrowth removing on a regular basis depending on the species of the tree and it's location.