.. Most of the big trees have preservation orders on them
so I can't do anything with them (not that I'd want to anyway).

Please don't think that a preservation order is a cast iron case that you
cannot do anything with them. They can even be chopped down. We have had a
blanket preservation order removed, TPO (Tree Preservation Orders) placed on
certain ones and felled the rest.

It is not the ogre many people think it is. They can be felled for instance
is they are in danger of damaging people or property, subject to
consultation of course.

Mike
been there, done that, got the tree shirt