Stop in for a cup of coffee

Mopar Tim said
Works great....
2.5 Inch Copper Nails for Killing Trees, Stumps & Roots - 10 Count | eBay

If you want to kill a tree, just gird it. It’s what the US forestry service does.

https://www.fs.fed.us/eng/pubs/pdfpubs/pdf99242809/pdf99242809pt01.pdf

Girdling - Wikipedia