The water from efficient tree irrigation is required not only for the biochemical processes involved in photosynthesis, respiration, and transport, but also for mechanical support to leaf and stem tissue. Insufficient (or inefficient) tree watering will result in loss of leaf turgor and a consequent reduction in new shoot extension. Eventually this will lead to die-back and, if not remedied, the loss of the tree.
Waiting until a tree shows a sign of drought stress before it is watered is known as ‘reactive’ tree irrigation. Whilst this might keep the tree alive, it will often result in stem die-back and possibly long-term structural defects in the tree. Research has shown that proactive tree irrigation, via implementation of a regular watering scheme, results in over three times the weight of new roots growing into back-filled soil material.