Yeah, I'm a bad neighbor. I have bishops weed under the buckthorn under pines that need to be cut down. The buckthorns are volunteers and provide a decent screen where a fence is forbidden. Even the little ones are tough to simply pull out of clay. The bishops weed also volunteered and keeps the pine cones from washing into my neighbor's yard in a hard rain. It's an ecosystem that works - for me - if I keep an eye on it.