This is a great video. It tells you all you need to know. Layed hedges, especially those with a ditch and bank and using a lot of thorn species is a very solid barrier indeed. When I get on some land (hopefully REALLY soon) I'm planning on planting for this kind of hedge.
Apparently I'll need to plant on 20cm (9 inch) centers and wait until they are 2.5m (8ft) high before the first laying.
France Zone 7a 1025mm rain, 1900 sunshine hours.
Just the other day, I was thinking ... about this tiny ad:
100th Issue of Permaculture Magazine - now FREE for a while