One of the main points of focus in permaculture is the use of perennial plants as opposed to annuals. Here in the Florida Keys, many plants that are usually considered annuals can be grown as perennials. For example, I once had a pepper plants in my AP system for over 3 years, and Ive grown the same basil plants for about the same duration.
Right now, Im trying to focus on perennial, heat loving greens in the system, so I have moringa, katuk, malabar spinach and some others in AP.