[Verity]

Right beside the trunk we have an ants nest.  They are the very large black ones and are going up and down the tree.  Are they beneficial to the tree?  I also wonder if the nest could be a problem to the roots.   Should I leave them there or get rid of them if so how?  I was considering putting a hose down the hole.  Advice would be much appreciated.  The tree is now about six years old and doing very well.

[John J]

Hi Verity, the ants themselves shouldn't be doing any damage to your tree, but it probably means that you have aphids that they are 'farming'.
Several methods of removing them can be found on the Internet, such as hosing (as you mentioned), spraying the tree with vinegar, putting a band of sticky tape/trap around the trunk and branches, etc, etc, etc. Take a look on the Internet and choose your favourite method!