Q.Killing nightshade
How to kill nightshade when it is growing up through a large shrub and can’t get to the roots? I was away for a couple of weeks and it had grown up through the shrub and across my small stoop. I had to cut it to enter the house. Later I identified it as nightshade and thoroughly washed my hands and arms.

If you are unable to dig up by the roots, then you will have to use an herbicide that contains glyphosate, which is discussed in the following article:
https://www.gardeningknowhow.com/plant-problems/weeds/get-rid-nightshade.htm