55. "bamboo's no joke. Concrete is about the only barrier that works." In response to In response to 7
and my understanding is that you have to go down 18" or more depending on the type of bamboo. And even then the runners can climb over it.
If she'll let you, you can take out that bamboo (if you even can; it can be really hard to eradicate) and switch to clumping bamboo, which still spreads, just much less aggressively than the running types. you should be able to clump them well enough to provide a screen.
I have a friend who put bamboo in about ten years back as a screen against the Wawa behind his house. I gave him the same advice about building a barrier. He didn't listen. Now there's bamboo growing in the damn parking lot and he has to go around into the Wawa parking lot to cut it down a few times a year.