Decorative Container Gardens - Making them Useful!

I recently applied for a job designing container gardens and patio gardens for city-dwellers in Philadelphia. Before considering this job, I hadn't given much thought to permaculture design on the scale of a container garden. However, for city residents without much green space, small containers can be the only option. I can definitely see how microclimates, zones, sectors, and other permaculture techniques can be used for the design of a space. But, this really got me thinking about how some clients might not think about the functional aspects, and only care about the aesthetics of the garden. It would be fun to introduce these city folk to the idea of actually using the things that grow in a garden. So, I started thinking about decorative herbs, and flowers that are edible and medicinal. The more decorative, the better, but I'm also trying to incorporate that functional aspect.

Just as I was thinking about this, I got an email from a seed company with the subject, "Eye-catching Edible Flowers," which is exactly what I'm thinking about. They suggested calendula, nasturtium, and dianthus.

Does anyone have any other ideas for making decorative container gardens into a functional addition to a city home? Has anyone seen container gardens with multiple funcitons? Juliet, is this a topic that you cover in the book, or does it focus more on the functional aspect of permaculture in pots?

It's not something I really cover in the book I'm afraid, but I absolutely think that things can be both decorative and useful

Fennel is pretty. Courgette flowers are gorgeous but admittedly they're only pretty for a brief while. Nasturtiums, marigolds... Mint and rosemary smell good as well as being edible (and rosemary has pretty flowers when it flowers, and is both medicinal and edible). I think tomato plants are pretty but I may be alone in this.

I do like multiple functions -- a garden (whether container or otherwise) should be a place to feel good in as well as to produce food. What 'feel good' means to different people varies, of course -- I don't really care for flowers that aren't also either edible or useful, myself but other people feel very differently and that is fair enough!

You can also decorate the containers themselves!

I will come back with more ideas; my dinner is ready