Why do we prune?
Manage growth - Correct structural problems while the tree is small - Aesthetic beauty- Because it is fun!
Types of Pruning
Thinning - the act of removing competing foliage within the crown of a tree or shrub to improve air flow, improve looks and to enhance structure. This type of pruning has many applications.
Reduction pruning - A very useful tool in keeping trees and shrubs small(er). Larger trees with defects such as decay, weak crotches, etc can be preserved by making them shorter and less of a target to wind. Many trees are removed by tree companies which could have been given a longer lease on life by reduction pruning . Reduction pruning relies on cutting branches back to laterals or natural growing points. This NOT the same as tree topping.
Structural pruning - Often structural problems trees encounter could have been avoided had its branching structure been pruned while the tree was small. Co-dominate stems with sharp angled crotches or "forks" are often the "weak link in the chain" resulting in failure during wind storms.
Clouding - a type of thinning whereby openings are made to allow sunlight to reach inside the plant to encourage inside growth. This is how boxwoods should be pruned.
Shearing - Reserved for shrubs - where by the outside foliage is cut along an even plane. I often see Large hollies and hemlocks at the corners of home that are sheared. This becomes a maintenance nightmare as the act of shearing stimulates rapid new growth.
Natural pruning - a form of reduction pruning whereby leaders are pruned back to a natural growing points. The plant looks more natural and rapid regrowth is not stimulated as with shearing.
Deadwood removal - When a limb, branch or any part of a tree or shrub dies, the plant is throug. Removal of deadwood makes trees and shrubs much more attractive. As an act of sanitation , is also a good practice.
Tree Topping - generally a poor practice which should be avoided if at all possible. Topping messes up the metabolism of trees resulting in rapid regrowth , results in root death and opens the door to potential future structural problems. Topping creates trees with un-natural crowns. One could argue that this is a form of reduction pruning with the same effects as shearing . Trees are not shrubs! However, there are some cases where topping cuts can be a good option in restoring a declining crown.