Trying to Kill Campsis Radicans/Red Trumpet Vine
I'm trying to kill a red Campsis Radicans (a trumpet vine), as this thing is popping up everywhere and trying to take over. I'm using boiling water to try and kill the shoots I see so far. We're hoping to put a lawn border, to at leas try and contain the vines, but the lawn border is about 8 inches in height. Is it possible for the vine to grow downward, to go eight inches below ground to try and reach past the lawn border and grow into the yard.
Please, any help would be fantastic. I hate this plant. :o(