Question

what should we do to kill a tree entirely

Answer 1

To kill a tree entirely you should uproot it from the roots of the tree.

Answer 2

Explanation:

The best ways to kill a tree without cutting it down is to drill holes in the roots and apply a tree killer, to girdle the tree, or to hammer copper nails into the roots. Warning: damaging other peoples property is against the law. You have to use a tree killer that actually works. Roundup may not kill the tree.