I didn't want to tread all over thistle down the middle of the tunnel area so I'm weeding and surrounding the enemy from all sides.
I know this horse thistle well enough now that I also found that the first year's growth has no thorns and looks kinda nice. They also pull out with the full root intact which is good.
Screw that poison. Pulled a lot of stuff that can go to the compost pile that I inadvertently started this morning while weeding the LFYG. I needed to do something with the holes leftover from moving the comfrey anyway.