as long as they have water they just inhibit the height. leave em alone. It is
unlikely they will generate new growth and they WILL look nasty forever.
Ingrid

- Is it possible that the trees could choke each other out or can they
survive close to each other?

- If he does remove a row will the previously unexposed side of the
tree generate new growth or will the just look nasty forever.

Thanks for the help.