Trees use their leaves to capture light energy from the sun and convert it into chemical energy. This process is called photosynthesis. Every time a tree is pruned it reduces its ability to feed itself so pruning must always remove the least amount of canopy volume. In unusual circumstances, such as to tidy up after storm damage, a significant portion of the canopy may be removed but always in accordance with Australian Standards. A qualified arborist can advise what is best in each unique situation. 

Trees should not be pruned every year. They need time to replace that leaf surface area that they have lost before pruning can occur again. 

Case study

Jinlong lives in an apartment which has a row of upright Birch trees planted quite close to the building.

As the trees grow, some of the branches have started to touch the windows. Jinlong is worried that they will cause damage. 

In this case, an arborist should be engaged to formatively prune the trees every 3-4 years. This will involve removing the branches that are growing towards the building but allow the trees to retain enough canopy to continue to grow upwards.