A tree crown reduction is an operation that reduces the overall size of a tree’s crown by shortening all stems and branches by a specific amount. This amount is now normally stipulated in metres.
Trees are normally reduced for two reasons. The most common is when a tree has outgrown it’s location and is blocking light or interfering with surrounding man made structures such as buildings, power lines or highways. A tree crown reduction will temporarily put a stop to the interference. The second most common reason is for safety. If a tree is found to be unsafe due to structural weakness, in the stem and/or roots, it can often be safely retained by reducing the crown of the tree. This not only reduces the overall weight of the tree but it reduces the wind resistance or “Sail effect” and allows air to pass through the tree crown more freely. As a result the tree is far less likely collapse in strong wind.
Thoughtful tree crown reduction
A well executed tree crown reduction retains the main framework, and natural shape, of the tree crown leaving a high proportion of the foliage-bearing structure which is important for maintaining vitality. It is important to consider the natural habit of individual tree species and to use this as a guide when making decisions about branch removal. The aim is to end up with as natural a looking tree as possible whilst removing enough of the crown to alleviate the interference issues. Generally speaking, the more material you remove from the tree crown (a “hard reduction”) the more difficult it is to produce a natural looking tree.
Not all species or individual trees are appropriate candidates for tree reduction work. This is usually either because of the species’ poor wound and decay defences or the reaction re-growth which can look unsightly.
Reduce tree crowns with caution
The reduction of a tree crown does, unfortunately, have the potential to impact negatively on tree health and should not be carried out in addition to other tree crown pruning operations. The removal of more than 30% of the volume of the tree crown can sometimes cause a tree to perish, particularly if the reduction is in addition to other pruning work or if the tree is already under stress from disease, injury or environmental complications.to top