See Hes wrote:Hi all,
5. What other features should a hedgerow have?
In the US Midwest the old saying is "Horse high, bull strong, and pig tight" for the perfect hedge. If a horse can't jump it, a bull can't push through it, and a hog can't squeeze out of it, then you have done it right. Here Osage Orange was used a lot.
It has nasty thorns and grows very tight and dense when trained. In Europe I believe hazel is more common.
I don't have any experience with Zone 11, but osage will go in zone 10, so I don't think it would be much of a stretch. Osage also can tolerate the drought conditions the Plains can experience, so wet/dry season cycles should not be an issue. The only deficit is lack of marketable product. While osage is a very hard wood with a high BTU content for heat, only the female plant produces a fruit, known as a 'hedge apple'. They are not very tasty as they are high in tannins. Horse will eat the fruit, but not a favorite. The wood is very durable and does not rot or decay (or very very slowly) even in contact with the ground. Makes great handles and small work working. Coppices well for burning with one of the highest heat release of all wood.
I have always thought bamboo would make a great barrier, although slow to establish. Cut cured culms woven into living standing bamboo would make an impenetrable wall once established. Then a thorny vining plant could be trellised onto to it for a deterrent.