This is a cry for help. A year ago, I bought three tiny Chinese Lantern plants at a perennial sale, and while I usually do online research on plants, I didn't do it last year because I figured the place holding the plant sale wouldn't sell anything invasive. I planted them in a small strip between the brick foundation of the house and a cement walkway. This year, I noticed how they spread, and it made me nervous enough to do that research I should have done last year. A few weeks ago I started to dig them out, but they keep sprouting. Questions: Is it easier to obliterate these when it's only been two years? Are they able to travel under cement slabs? And, if I apply Roundup to the roots in the soil as well as the leaves of the sprouts, will the chemical kill the roots that way, or only via the leaves? I am sick over this. I'm afraid they'll spread into the nearby peonies, and the Roundup will likely kill my sedum, Shasta daisies and flax.