Permaculture isn't only about the practical; or rather, "practical" covers more than you might think. Permaculture is all about sustainability, and that includes creating environments which are sustainable for humans in respect to all their needs.
A garden needn't just be about food to be practical, sustaining, and sustainable; it can also be about beauty, or fun, or rest. Of course, food plants can also be beautiful (rainbow chard is one excellent example; or the little blue flowers that appeared on my rosemary bush in early spring). But the beauty in non-edible plants means that they're also a worthwhile addition to the garden, simply for the joy of looking at them. And a garden you want to spend time in is invariably a more productive garden.
Which is to say that I have a bunch of flowers in our garden now, along the western fence by the rosemary and the raspberries. The first to go in, last autumn, were winter pansies. Pansies are my favourite flower, and their January blooms cheered me up no end. More recently I put in some forget-me-nots, which are very practical flowers in that they are self-seeding, but easy to pull out, so low maintenance in both directions. As mentioned in the peas and beans post, there are also now a few pots of sweet peas to make the patio smell lovely when they flower. And finally, a few evening primroses in with the pansies, because my Mum had some spares and it would have been a shame to waste them. (Actually, all the flowers were spares from my Mum. Thank you!).
Pansies and raspberries (and some purple wild flowers that I don't know the name of) earlier in the spring