Hello, I chopped down this plant a month ago when it was ten feet tall and it grew right back even bigger than before. It looks like it was purposely planted in front of my deck because of the concentration of them. It has red spotted hollow stems with flat-sided heart shaped leaves. I have never seen flowers on the plant, even at 15 feet tall. ????????? I just would like to know what I am battling. Thanks.
Japanese knotweed. Much talk about that one these days. Sometimes people actually have other species of knotweeds, but same difference in terms of weediness.
As Ron B alluded to, search through the forums for plenty of discussions on eradicating this nasty invasive.