My next door neighbours garden is extremely overgrown, think very overgrown trees (well over 2m high), bushes, weeds, nettles etc. They literally can't step out of their back door as it's so overgrown. This didn't bother me until recently when the trees have grown massively and are leaning over into my garden, blocking the sun, the weeds are now starting to grow through the fence into my garden too.
Is there anything I can do about this or do I just have to put up with it and cut down whatever comes on to my side? I don't know if they rent or own of that makes any difference.