When Trees are planted further apart than 5metres, it becomes economic and sensible to use a polytube "Spine” to carry the water from tree-to-tree, then tee off to each tree with a spiral of Leaky Pipe.    This negates the water being applied between each tree, saving that cost and also helping to discourage weed growth in that area.

When watering Extra Heavy Stock, (very large trees!) the Leaky Pipe Spiral needs to water three important areas.  It needs to water the root ball, (to keep the tree happy), the new soil surrounding it and really importantly, the margin between the two.  The reason for this is that it would be deleterious to root growth across from the rootball to the new soil, should the margin area have the conditions to allow it to shrink away from eachother, (as in Drought).  This will cause "checking” in the tree establishment and will affect the subsequent growth.  After the first Year, it can be sensible to relocate or limit the spiral so the rootball is no longer watered, to encourage roots out from under the tree, aiding structural rooting.