Oops, the word processor jammed up a bit before I was finished blathering on and on.
The river bamboo mentioned is called Arundo Donax, and it's not really a bamboo, it just sort of looks like one. It's also free to propagate as long as you know where some's growing. It is fast, but not much of a security barrier. It might be a cash crop though, for some enterprisiong American farmer. This is the palnt from which all reeds for woodwind instruments is made. The only hitrch is that the process requires that cut canes be submerged for ten years after they are harvested, then they can be dragged out and cut up to make the raw materials from which woodwind reeds can be produced. Right now I think a few French companies have a worldwide monopoly on the production of woodwind cane. Maybe you'll be the one to break that monopoly.
A good barrier planting has several layers. Tall plants to obscure, spiny plants to annoy, and thick plants to obstruct passage. I've made a few barrier plantings, and my favorite addition was always Puncture Vine. Looks like a nice little low growing weed, but the hard pointy seed pods can pop a bicycle tire and certainly go right through a tennis shoe sole. Dogs hate the stuff.
Other great barrier species:
Pyracantha, Blackberries, Poison Oak, Roses, and Barberry.
Happy Sadistic Landscaping!
-Rick
