Do you mean that you can kill a daylily?? My DH always gets a little carried away with the round-up and it may stunt a few for a week or two, but they recover fast. I've left them way way toooooo long without any care and they still grew, in pots! I even had some that I've left laying on the ground, forgotten and discover them the next year, blooming! So, you must use some heavy duty stuff to change a dip to a tet. Be careful, it might make a girl into a boy!!!