Fill the holes completely with Epsom salts and pour water into them. Avoid overfilling, as the salt solution is harmful to surrounding vegetation. Repeat this process several times for a few months. Sooner or later, the salt will kill the tree roots.

What kills tree roots fast?

The fastest, most effective way to kill roots is with chemical herbicide, as soon as the tree has been cut down.

What chemical kills tree roots?

Dicamba, imazapyr, picloram, glyphosphate and triclopyr are chemicals found in herbicides for stump and root-killing.