We have a conifer hedge at the bottom of our garden (and no, we didn't plant it, the previous owner did). We get it trimmed about every 3 years, as it grows fast and every time we get the tree surgeons do it, I get a text from neighbour asking 'Can you get them to do our side?'. The 'our side' that they're talking about is just one tree's width that hangs over their fence (see diagram). It's not a big job and when there's been time in the past I've asked the tree surgeons to do it, but it strikes me as a bit cheeky and I'd never ask for someone else to pay to cut something that was hanging over my fence - I'd just do it myself.
However, it is our hedge, so my question is this: is it our job/are we obliged to do this? I know that they're entitled to cut anything that hangs over their garden and we cut anything that hangs over ours and I know it's nice to be neighbourly and generally speaking we are and we have a good relationship with them - putting each other's bins out and feeding each other's pets when one of us is away - but are we actually meant to cut this area as it's our hedge? All the info online talks about rights (i.e. the right to trim anything that overhangs your garden and the necessity to offer the trimmings or any fallen fruit back to the owner), but I can't find anything about whether we are obligated to offer or to trim the hedge ourselves. Does anyone know the legal position?