Question
I live in california where most herbicides are now illegal.  I have a medium size olive tree I need to remove as entirely as possible, including the roots (at least killing them!)  I do not want it getting into the neighbors yard.  The roots seem to be growing/going DOWNward, in my yard, but cant be totally sure,,can you suggest best way to rid this beast!?  thanx

Answer
Cut the tree at ground level and treat the stump with a product called sucker stoper. It is made in California so it should be able to be used there. Check with your local garden type store for this product. You can just cut the tree and grind the stump down below the ground level. You may get some sprouts and if so cut them as soon as they come up from the roots. The roots will try to grow foliage by sprouting but if you keep them cut off the roots will die. It may take a season for the roots to stop sprouting. Ofcourse the best method would be painting the cut stump with roundup. I do not know if you can use it there. If not I am sorry.
I hope this helps.