Involves the removal of the lower branches to a given height above ground level, it is achieved either by the removal of whole branches, or by the removal of only those parts which extend below the desired clear height. This process is normally carried out where there is a need to clear footpaths, roads, signs and also allows for increased light. UK common practice clearance for vehicles is 5.2 metres (17 ft) and for pedestrians 2.5 metres (8 ft).
Trees can be reduced in height and / or spread while preserving a natural tree shape by crown reduction. Very substantial crown reductions should, ideally, not be made during a single growing season since severe loss of leaf area and multiple wounding may impair a tree’s defences against diseases and decay.
Involves the removal of a proportion of secondary and small, live branch growth from throughout the crown to produce an even density of foliage around a well spaced and balanced branch structure, it should usually be confined to broadleaf species. Crossing, weak, duplicated, dead and damaged branches should be removed.
Should aim to produce a tree which in maturity will be free from major physical weaknesses. Unwanted secondary leading shoots and potentially weak forks which could fail in adverse weather conditions, e.g. strong wind or snow, should be removed.
Should not be used on trees that have not previously been pollarded when they were young, as the large wounds created can initiate serious decay in mature and maturing trees.Very heavy pruning may kill some species (e.g. beech) while others will be stimulated to produce dense re-growth of shoots from around each wound. It should be noted that different species of trees respond to pollarding in different ways and pollarding may not be suitable. Willow Trees have an approximately 95% survival rate whereas Beech Trees rarely survive the procedure.
A pruning technique where a tree or shrub is cut to ground level, resulting in regeneration of new stems from the base. It is commonly used for rejuvenating old shrubs.