Before I can get gold out of my potential garden, I have to get the poison hemlock out.
Try
Bonide Vine and Stump Killer.
I used it in the fall;
applied directly to fresh stump/cut or even a leaf. It is very targeted - absorbed down to the roots, but leaves nearby by plants alone.
I was able to remove an aggressive wild vine type rose that the birds gifted right next to a heritage lilac and a huge thistle with a deep tap root right in the midst of a flower garden successfully. The lilac and rest of the flower garden were untouched. Also used on small trees and uninvited aggressive honeysuckle. Personally I would not spray for fear of unintended consequences.