ProponentsFact: date=April 2008 of pruning often argue that it improves the health of the plant and makes sturdier structure, opponentsFact: date=April 2008 believe that pruning harms plants' "natural" forms and leads to wounding which may become infected.

In general the smaller the wound (smaller the branch that is cut) the less harm to the tree. It is therefore better to formative prune the tree when juvenile than try to cut off large branches on a mature tree.

There are also inconsistencies pertaining to pruning. How you would prune a rose, shrub, hedge, fruit tree and an amenity tree may be different.

Consequences with incorrect pruning performed to large trees can be dangerous. If a shrub was incorrectly pruned and a piece broke off it may not do much damage. However if a tree next to the house was incorrectly pruned and a large branch fell from 50 feet (about 15 metres) it could be deadly.

Pruning Landscape and Amenity Trees

Branch structure and how they are attached to each other in trees falls into 3 categories. Collared unions, collarless unions and codominant unions. Each specific attachment has its own unique way of being cut so that the branch has less chance of regrowth from the cut area and best chance of sealing over and compartmentalising decay. This means that there are 3 types of cuts made, whether that be to remove a little branch coming of another or cutting a whole branch off back to the trunk. This term is often referred to by arborists as "target cutting".

Some of the terms used predominantly by arborists and what they entail:

Dead Wooding

Removal of dead and decaying branches from the tree to minimise the risk of damage to property/injury to people.

Crown - Canopy Thinning

Increase light and reduce wind resistance by selective removal of branches throughout the canopy of the tree. This is a common practice which improves the tree's strength against adverse weather conditions as the wind can pass through the tree resulting in less "load" being placed on the tree. Generally performed on trees that do not have a dense impenetrable canopy as opening a 100% dense canopy up with holes for wind to enter can result in broken branches and uprooting.

Crown Canopy Lifting

Removal of lower branches. Increase clearance for property, people and vehicles.

Directional or Formative Pruning

Removal of appropriate branches to make the tree structurally sound whilst shaping it.

Vista Pruning

Selectively pruning a window of view in a tree.

Crown Reduction

Reducing the height and or spread of a tree by selectively cutting back to smaller branches.

Pollarding

A regular form of pruning where certain deciduous species are pruned back to pollard heads every year in the dormant period. This practice is commenced on juvenile trees so they can adapt to the harshness of the practice.