I had a teenager moving some day lilies for me. He was concerned that he was going to destroy them because the ground was really hard and dry. I told him he might could kill them with roundup, but I didn't think he could kill them on purpose with a shovel.
Several months later and the ones I separated and planted look good. The ones I got tired and left on the ground in a pile look good, too. The ones he gave up on and left alone look really good. They are going to take over my rose bed if something doesn't happen soon. Roundup?