Often carried out where more Head room is needed underneath trees branch's giving clearance for People and Vehicles beneath trees.
Crown lifting is the procedure adopted. This involves the complete or partial removal of branches to give a specified clearance from the ground, to give unhindered movement around the tree.
Extensive crown lifting should if possible be phased over a number of years, with a view to providing some opportunity for physiological and biomechanical adaptation to the resulting wounding and branch removal.
Crown lifting should be avoided or minimized in mature or old trees if possible, since it can increase the probability of stem failure
Crown lifting that involves cutting back branches to the stem(s) should preferably not result in the removal of more than 15% of the live crown height
The effects on the tree of both seasonal factors and weather conditions should be taken into account before pruning is undertaken Ideally, as a general principle for maintenance of vitality, trees should not be pruned during periods of water stress or during spring growth (when sugar and starch reserves are depleted), until new leaves have fully expanded and matured, or starch reserves have been replenished. Sufficient time should be allowed for a tree to recover following any damage or adverse management that might have increased its vulnerability to physiological dysfunction, before carrying out any further extensive pruning.
Any works should be planned so as to limit their potential adverse impact following Bs3998 guidelines to minimise distruption to wildlife generally follow the Wildlife & Countryside act; i.e. Bird Nesting season.