Tree Pruning Techniques that Won't Harm the Tree
Within the niche of tree care, tree pruning is among the most basic of tasks. Pruning is an uncomplicated process that refers to the periodic removal of certain parts of the tree to improve its overall health and define its growth pattern. However, if done improperly, tree pruning can prove disastrous. Injuries to the tree caused by poor tree pruning techniques can further lead to depletion of the tree’s nutrition along with delaying the development of flowers or fruits and making it more susceptible to diseases. Tree pruning techniques that are recommended for the tree's safety include the following.
1. Tree Pruning with Crown Thinning
A tree’s crown is the general term used to indicate the branches, stems and leaves growing aboveground from the trunk. Crown thinning involves the removal of branches/stems to reduce the overall volume of the tree’s foliage. Crown thinning is done for a variety of reasons. This is often done to address issues such as blocking of sunlight by the tree. Crown thinning usually doesn’t need much planning or following of a certain pattern. However, it can be laborious with trees with thick branches, which might require the use of heavy pruning equipment. It also helps to improve the appearance of a tree, as less-dense crowns allow more sunlight to filter through and are aesthetically more appealing.
Crown thinning is usually required among hardwood trees. Such trees tend to develop a dense network of branches than can block the supply of light and air to the lower branches. However, crown thinning should be done in a restrained manner. Excessive thinning can drastically reduce the foliage cover and can cause scalding and weakening of the inner, weaker branches. Branches further away from the trunk and those than tend to cross/intertwine are preferred for crown thinning. It is advised not to reduce more than 25% of the crown during a pruning session.
2. Crown Lifting/Crown Raising Tree Pruning
Crown lifting is slightly different from crown thinning. While crown thinning is essentially aimed at upper branches of the three, crown lifting is aimed at the lowermost branches, i.e. branches just below the tree’s crown are removed. This is often done in trees with dense foliage wherein the increasing size of the crown tends to hamper the view. Crown thinning is more common among trees growing in public places where the tree’s foliage can hamper the view of the pedestrians and motorists, causing accidents.
It is usually recommended not to prune more than 33% of the lower branches. In young trees, retaining the younger branches is often vital to encourage proper tree growth, and thus, the pruning is a bit restricted here. Furthermore, younger trunks are more prone to sun-scalding and thus, the pruning volume should be reduced.
3. Crown Reduction Tree Pruning Method
Crown reduction is a more invasive form of pruning as compared to the above two options. This pruning technique is aimed at reducing the overall size of the crown while maintaining its original outline. Crown reduction is much better than damaging pruning methods like topping, wherein larger, more upright branches of the tree are pruned off. Crown reduction pruning uses intermodal cuts in which the tips of the longer branches are cut back to an inner branch. Crown reduction pruning is done by the following ways:
- Removing dead and diseased branches
- Cutting back the taller upright and perimeter branches close to secondary (inner) branches
Crown reduction is limited to the taller trees with an aggressively-expanding crown. Such trees often pose problems like the crown intruding into a neighborhood building, pushing against electrical wires, or casting shadows in an adjacent property. Crown reduction is usually combined with crown thinning or crown lifting at a later stage to ensure that the tree doesn’t regain a problematic dimension. Crown reduction is also referred to as "drop crotch pruning." It ensures a more natural appearance for the pruned tree and induces minimal stress since the pruning is uniformly spread across the entire crown.