Before launching into 8 super-cool permaculture herbs, let's talk about permaculture. Permaculture is an ecological design science that is modeled after nature and used to create sustainable human settlements.
Here's a "grow-your-own fence" - the pollarded willows not only supply the withes, they're also the fence posts. Permaculture is big on plants having multiple uses. It doesn't get much more "multiple" than this.