On Saturday, 20 March 2021 at 10:33:06 UTC, Chris Green wrote:
I think you're after a virtually non-existent tool/machine. I have a
similar issue (I think) on a larger scale, trimming around a large area
of lawn and under (lower than they should be) trees in an orchard.

I have never (and I've been searching for 20 years or more) found a
simple, 'easy' (as in not tiring) way of doing this.

In the main it comes down to 'some sort of strimmer', since I have a
lot of various types to do I have more than one strimmer but which
ever you use it's hard work. One of the better approaches I found was
a Bosch grass trimmer with wheels but it wasn't really big and tough
enough for my requirements. A strimmer with wheels *might* go some of
the way to what you need though, much more controllable and less hard
work when you don't have to support the business end.

You could be right there!