Buy yourself a chain sharpening kit at the same time, and a spare chain.
You may not need it if that is all you are going to do and it depends on how hard the wood is and how many there are and if you intend to cut them up once you've got the hedge down.
I only use ours on hardwood as I use it to saw up logs for the fire, but I have also used it, on its side, to clear some self-seeded oak trees off a piece of land we don't use. So I need to sharpen it about every two tankfuls of fuel. It maybe that I am not the best sharpener in the world but it does me.
