Is disappearing the same as killing? I've had a few of those. Daffodils (but this saved me the work of doing them in), Cardinal Flower, Swamp Milkweed.
Oh this was terrible. The first year we planted anything... tulip bulbs in our new to us house back in Omaha. We followed directions to a T. They never came up, but strangely that variety of tulip popped up in the middle of the backyard neighbour's lawn. Once they discovered them, they even mowed around the tulips. I doubt they were tulip thieves, but possibly a squirrel?? That's not a killing though.
I have given up on trying to kill that lilac by the porch. Shoots kept coming up (no chemical use here). I learned even though they are not native, they don't spread like some things, so maybe I'll just surrender.
But since a serviceberry was planted near there, that takes precedence, even if the lilac gets a weird pruning now and again. Oh, but every hint of a flower that dares show its face gets cut off. That smell.. (Need a barfy face).