Lons":1g3hmmhv said:
I don't envy anyone trying to dig post holes among the roots those tress will have put out!
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too right - when ive done it in the past ive use a power auger but it isnt easy and also doesnt do the trees much good.
one option would be to get the school to put the fence on their side - ie between garage and wall up to the height of the pruning - but that is likely to be prohibitively expensive
the alternative would be a four strand or whatever barbed wire fence behind the trees on your side. Despite comments on the other thread given that the kids have a wall and a line of leylandi between them and the wire i cant see it being much of an H&S threat. - you could then grow dog wood or whater ornamental you like inside the wire to hide it from your view.
and a third option would be to fell the leylandi completely and replace with a fence - maybe projected out on its posts to be in line with the wall edge to make it virtually unclimbable
btw soulfly is talking out of his proverbial orifice (no major suprise there) pyracantha is as clasic hedging plant, but i dont think it will survive under the leylandii - though of course you could go the fence behind route as above and then put a pyracantha and/or berberis hedge beyond that fence to both hide it from your garden and also to provide a tertiary barrier.