getting rid of old holly tree near arbutus

I chopped down a holly tree a few years ago and planted a small arbutus nearby. I should have taken a stump grinder to it, but hindsight is everything. I don't want to disturb the roots of the arbutus by trying to dig it out, so I'm forever cutting back the new holly growth. Any ideas about how I can get rid of the holly without harming the arbutus?

 

Hmmm. You could cut it to the ground and put black plastic over it.

Every-time you check under the plastic, you can pull off any green growth that may be trying to live.

I would think that eventually it will wither away.

 

I got rid of one by scraping the bark off all round the trunk with a trowel, as deep as I could go.