We have a ditch right on the other side of our evergreen trees that in the past we let overgrow. Bushes, trees, and not to mention that darn thistle, started to take over. This year, I made a major effort to keep it mowed. We found that consist mowing really helps! It allows the grass to thrive, while suppressing the unwanted stuff.
Not sure if that’s an option for you, but I found it effective.