Killing a tree stump with salt or copper nails

Question

I have allowed some trees to grow from this tree. Will it kill those trees as well? They are probably 50′ from the stumps. The trees in question are cottonwood trees, two of them were mature when the host tree was cut down. I wish to stop more trees growing from these stumps. Does it just stop future runners or endanger existing ones? Thank you for your answer.

Answer 1

This article will help you.
https://www.gardeningknowhow.com/ornamental/trees/tgen/kill-zombie-tree-stump.htm