Boundary/ hedge suggestions to go next to/ under fir trees?

[DontKnowAnythingAnymore]

It Could be leylandii (not sure) that the neighbours have on the boundary (they own). They are higher than us and I worry that one day they’ll cut them back and we’ll have no privacy whatsoever.

I was thinking of planting something on our side, but close that could mitigate against that. They’re not the best neighbours with regards noise and mess, so I really want something that would help to create a really good boundary.

Does anything exist? I worry that nothing will grow so close to the trees.

In the north/ Scotland, so needs to cope with harsher winters or wetter summers.

They do something to make the soil acidic so that needs to be taken into account. Holly works though and doesn’t mind the wet or cold.

Are some hollies denser than others? There are actually some holly bushes nearby, but they are very 'open' - not hedge-like.

Ideally they’d be at least 6-8 ft when grown.

Bump

Very little will grow successfully near or under Leylandii.

If you want an impenetrable hedge try putting a wire fence up first and then plant acid loving shrubs - rhododendron, phoning etc make nice hedges.
Not relevant but I had 30ft leylandia in my last garden. I grew clematis Montana up them and they were stunning. The trees left the ground very dry though .

Yes, I think I will have to do that. I was trying to avoid fencing due to the cost, but that might not be possible.

The shade will be dense. And the soil thin , dry and rooty. I put a large wooden planter in such a position, and grew berberis and honeysuckle. They probably won’t chop them down though. Sounds like a problem for another day!