How do we kill the roots of an annoying bush next to the house?

Hi Beth the best way to truly get rid of it would be to dig it up and get every last root.

Cut the main stem down to a couple of inches. Use Roundup or another strong weed killer on the fresh cut with a paint brush. This will allow the poison to reach the roots quicker and easier. You can do this multiple times, just make sure that you have the surface roughed or freshly cut when you reapply it. I did this with a huge wild grape vine, they are super tenacious, so that it took me nearly a year to not get anymore sprouts coming out of it. It was trying to kill a lilac and go into the neighbors siding. Your bush may not be as hard to kill the roots. Good luck, Beth!

Thank you, Nancy! Good idea!