Pruning and Removing Trees
Pruning is the most common tree maintenance procedure. Although natural forest trees grow perfectly well on their own planted landscape trees require a higher level of care to maintain their structural integrity and aesthetics. Pruning must be done with an understanding of tree biology. Improper pruning can create lasting damage or even shorten a tree's life.
Often small trees and shrubs, such as fruit trees, can easily be managed yourself. You can find out more about the right way to prune on our Tree Care Information page.
Pruning and removing larger trees is a dangerous task involving large, heavy structures, dangerous equipment and working at heights. For your safety and the protection of your property these activites should only be undertaken by a competent, qualified and insured arborist.
Often a professional consultant arborst can provide advice to you regarding trees on your property that means your tree may not need to be pruned or removed, preserving the tree and saving you money.
In many places council or state controls may require you to obtain a permit to prune or remove a tree, particularly if the tree is large or a local native species. Check with your local council for controls in your area.
Because each cut has the potential to change the growth of the tree, no branch should be removed without a reason. Common reasons for pruning are to remove dead branches, to improve form and to reduce risk. Trees may also be pruned to increase light and air penetration to the inside of the tree’s crown or to the landscape below. In most cases mature trees are pruned as corrective or preventive measures, as routine thinning does not necessarily improve the health of a tree
When to Prune
Most routine pruning that is undertaken to remove weak, diseased or dead limbs can be accomplished at any time during the year with little effect on the tree. As a rule, growth and wound closure are maximised if pruning takes place before the spring growth flush.
A few tree diseases can be spread when pruning wounds provide access to pathogens (disease-causing agents). Susceptible trees should not be pruned during active disease transmission periods.
Specific types of pruning may be necessary to maintain a mature tree in a healthy, safe and attractive condition.
- Cleaning is the removal of dead, dying, diseased, weakly attached and low-vigour branches from the crown of a tree.
- Thinning is selective branch removal to improve structure and to increase light penetration and air movement through the crown. Proper thinning opens the foliage of a tree, reduces weight on heavy limbs and helps retain the tree’s natural shape.
- Raising removes the lower branches from a tree to provide clearance for buildings, vehicles, pedestrians and to allow for clear sight-lines.
- Reduction reduces the size of a tree, often for utility line vegetation control clearance. Reducing a tree’s height or spread is best accomplished by pruning back the leaders and branch terminals to secondary branches that are large enough to assume the terminal roles (at least one-third the diameter of the cut stem). Careful and proper reduction helps maintain the form and structural integrity of the tree.
Pruning Young Trees
Proper pruning is essential in developing a tree with a strong structure and desirable form. Trees that receive the appropriate pruning measures while they are young will require less corrective pruning as they mature.
A good structure of primary branches should be established while the tree is young. These branches, called scaffold branches, are a mature tree's framework. Properly trained young trees will develop a strong structure that requires less corrective pruning as they mature. For most young trees maintain a single dominant leader growing upward. Do not prune back the tip of this leader or allow secondary branches to outgrow the main leader.
Pruning of palms is mostly done to remove dead or dying fronds and/or flowering/fruiting clusters, particularly those that may be a potential risk to the public, such as coconuts. Pruning is usually conducted at least bi-annually. Coconuts may be pruned as often as every 3-4 months to minimise the risk of injury or damage from the heavy fruit falling. Great care should be taken to avoid any damage to a palm's terminal bud or trunk when removing fronds.
It is best for the palm if green fronds remain intact. Overpruned palms may have slower growth and may attract pests. Climbing spikes should generally not be used to climb palms for pruning, because they wound the palm trunk.
Don’t Top Trees!
The act of 'topping' is perhaps the most harmful tree pruning practice known. Yet, despite more than 25 years of literature and seminars explaining its harmful effects, topping remains a common practice.
Topping is the indiscriminate cutting of tree branches to stubs or to lateral branches that are not large enough to assume the terminal role. Other names for topping include 'lopping', 'heading', 'tipping' and 'rounding-over'.
Alternatives to Topping
Sometimes a tree must be reduced in height or spread, such as for providing utility line clearance. There are recommended techniques for doing so. Small branches should be removed back to their point of origin. If a larger limb must be shortened, it should be pruned back to a lateral branch that is large enough (at least one-third the diameter of the limb being removed) to assume the terminal role. This method of branch reduction helps to preserve the natural form of the tree.
However, if large cuts are involved, the tree may not be able to naturally close over the wounds. Sometimes the best solution is to remove the tree and replace it with a species that is more appropriate for the site.