Killing a Big Buckthorn (rhamnus cathartica), a Highly Invasive Tree Using the Foam Herbicide Dispenser from Green Shoots

This video shows me taking down a large buckthorn tree.  I am using a chainsaw because this tree must be about ten inches in diameter and probably 80 to 100 years old.  After cutting off the tree and leaving a stump, I am applying foam herbicide using a dispenser being developed by Green Shoots.