We have a tall-ish hedge between our property and our neighbour's. Part of it is starting to lean over and I wondered whether it's possible to straighten it up
What kind of hedge is it? Is it leaning in order to get light? What height is the hedge? Is it top heavy....is it leaning because the top is wider and more heavy than the base of th hedge?
It's an ordinary old garden hedge, i think you would describe it as buxus(?). It's not leaning for light - i think it's because the top is heavy
If it's top heavy then the height needs reducing. I'd totally renovate the hedge - reduce it's height by at least two thirds, clear the base of any dead wood, weeds, grass etc and feed with Fish, Blood and Bone and water well - then stand well back.
If it's the sort I think you're describing (a small darkleaved evergreen) it'll produce new growth from lower down and you'll get a decent hedge again. This time don't let it get too tall