hello my name is ***** ***** I will help you.
Whose is the wall? Whose are the Trees?
Ok. If your trees are causing the issue then you would be liable.
This is because you have control and they emanate from your property. If it causes damage to the wall and that wall does not belong to you, then you would be liable.
If you own the wall and this is damaged and causes damage to something else then you would be liable.
You need a tree surgeon to come out and advise what to do. In short if your trees are causing damage to someone else's property or causes injury you sre liable.
They may be able to prune them back or offer some other advice.
Can I clairfy anything for you about this today please?
For that you would need a professional survey to determine to what extent, if any this has.
It the answer is none then you are liable. If the answer is some or all then you will not be liable.