Hinotori said:
So I have to cut down by hand, or try and drive the mower over. Then I must make sure I mow it at least every other week. Don't let the roots get nutrition from new growth so they eventually die. Takes years to kill those roots.
You mention a mower, Hinotori. Are you clear on what the difference between a mower and a rotovator is?
I'd be tempted to rotovate, and then use various hand-powered garden tools (hoe, claw) to get the roots out... pile them and burn them or something.
One big clean-up, and likely your annual drudgery with that yard would be reduced by 80% (just guessing).
Of course, I'm not familiar with
your terrain, wild vegetation, climate, and the like. And ~gd feels rotovating would be a bad idea. He recommends RoundUp.