re: What is the best way to kill a yellow jacket best in the ground?

I have used a 10' piece of pvc with a 90 attached on one end. Slowly push the pvc to where the entrance to the nest is, put a funnel in the 90 and slowly pour some gas into the funnel. It doesnt take a lot, maybe a cup or so of gas.

This allows you to get the gas where it needs to go without killing all your grass. The distance is usually enough to keep you from getting stung.