garden - trelis on fence

[spaced]

If I am attaching a trelis to both of my fences in my garden, do i have to ask for "authorisation" from my neighbour on the side whwre the fence isnt mine? I was told this yesterday but have never heard of it before!

[CheekyChops]

Strictly speaking yes, you are fixing a trellis to something that doesn't belong to you so you do need permission.

I doubt most people would be bothered though.