in tresco, scilly isles (uk), they make extenisve use of oleria hegdes, new zealand origin, fast growing, wch protect daffodil crop and veg fields from heavy westerly gales from the atlantic. they don't get much frost in tresco, but they are certainly resistant to mild frosts as i have them growing in my garden in london and they showed no ill effects after nightime temps of about -5c rgds cmb