Forget-Me-Nots. And especially English Daisies. I have been trying to root them out of my garden for years. They even pop up in the lawn in clumps. The daisies. The vinca seems to stay where I put it though I dug out a bunch under a huge spruce tree and put in some Bergenia. It grows really well here and is one of the first to flower then has lush leaves. I keep the dead stuff cut off.
