Tree in a container advise please

[Sounbelievablydull]

Hello there we have a brick trough style thing next to our fence. It had to be built there when we had an extension
It is approx 2 feet high and a foot wide.
It is exactly next to our neighbours fence and although we get on with them I would like to plant some tall screening style plants in there.
Any ideas?
I was wondering about some kind of trees?
We really only sit out in summer time so only need to cover that period

So is there fence between this trough and your neighbours, or just the trough?

Can things in the trough put their roots into the real ground, or is it totally enclosed?

Could you put a trellis panel behind the trough?

I think we needs pics!

Eeeeekk pics will reveal the horrors of the garden but can provide tomorrow in day light
Have currently got rosemary bushes in there but they need to be moved
It is up against the fence and yes is totally enclosed

If It's totally enclosed, you could consider bamboo, lots of kinds available.

If there's a chance of it escaping, though, avoid. Bamboo likes to spread! But it makes a great screen, and the noise of the breeze in bamboo is rather lovely.

Bamboo just be careful what type

It is not really deep enough for a tree. I would suggest Cornus or Salix. If you put Pots either side of it, you could plant honeysuckle and clematis or winter or summer jasmine. This will give you a good covering and perfume plus year round interest.

For fast coverage and if you can stand it, the. Russian vine will do the trick.