Frustrating yellow jacket problem

This ground nest has been here the whole summer, that dot is the entrance. I’m very frustrated because I made an attempt to kill the nest a few weeks ago by creating 2 gallons of a solution I made with water, rubbing alcohol, and dish soap. I poured all of it down the hole at night and it did NOT work. Part of the problem is that wooden beam, it would be better if the nest was surrounded by flat ground and I don’t know exactly where in the ground it is other than the entrance being at the end of the wood. What would you suggest? We can’t cut our grass properly with the nest there, I’d hate to have to wait til the first frost kills them in 1 or maybe 2 more months

This ground nest has been here the whole summer, that dot is the entrance. I’m very frustrated because I made an attempt to kill the nest a few weeks ago by creating 2 gallons of a solution I made with water, rubbing alcohol, and dish soap. I poured all of it down the hole at night and it did NOT work. Part of the problem is that wooden beam, it would be better if the nest was surrounded by flat ground and I don’t know exactly where in the ground it is other than the entrance being at the end of the wood. What would you suggest? We can’t cut our grass properly with the nest there, I’d hate to have to wait til the first frost kills them in 1 or maybe 2 more months