On Mon, 20 Feb 2012 17:49:59 +0000, Janet Tweedy wrote:
If it's the dogs you worry about then stock fencing would be fine.
Barbed wire won't keep much out in the way of humans as Janet said but
Stock fencing along a hedge however gappy would stop dogs getting
through and is considerably cheaper than chain link.

Or deer fencing, given that there's an existing hedge - it works out to
about 9p/foot here.