I know that a lot of folks find this plant to be a nuisance, but I'm adding it to the list of tough, and at least in my eyes, worthy plants. Stachys byzantine.
I've had Stachys byzantine for at least 6 years and I've only once seen a seedling out of the beds/areas I put it in, and that was where I tossed the clippings so you'd expect some there. I love them, the bees love them, and I wouldn't want to be without them. I do cut mine back after the first heavy flowering, and thin them down a bit at the same time, then cut them back before winter...perhaps that makes the difference? At any rate, I don't have to water or add mulch to those beds; the lamb's ears cover all exposed soil in between other plants and use little water themselves.
Beginning of season...
End of season...
It's so very different looking now, with heaps of branches and brush piled around the roses and everything so sparse and brown! I have put in some evergreens now to delineate the beds, that helps a little.
