what is the best way to kill the conocarpus up to the root

Question

I have more than 20 conocarpus trees surrounding my backyard but the roots are growing so fast and are so strong they have started to damage my house infrastructure.

I have tried to remove a few of them but the roots underground have started to re-grow and penetrate my floor through the tiles. I searched for a way to kill the trees up to the roots but could not find an answer. Some people had to dig their entire backyard and burn the roots but I cannot do that.

What can I do and make sure that they will never grow back again knowing that I cannot reach the roots under my backyard?

Answer 1

Typically with root problems like this, I recommend that you cut back the plant as much as possible and then as soon as the plant is cut, you paint the cuts with pure, undiluted Round-up. Painting the cuts right after they have been made will cause the plant to suck in the Round-up into its vascular system and this will carry it to the roots and kill them. For particularly hardy plants, you may need to do this two or three times (and do it as soon as you see any signs of new growth), but it will eventually kill off the roots.