When I first discovered permaculture, I took "obtain a yield" to mean I should only grow food plants in my garden. As I found out more, I realised that not all yields are measurable. How can you quantify the pleasure of looking at your favourite flowers or the delight in the scents of the garden? These are still yields. Flowers attract beneficial insects (and pests, unfortunately but they are part of the ecosystem too) and some, like nasturtiums, one of my favourites, are also edible. Nowadays I have a mixture of food plants and ornamental plants, often next to each other. Looking out of the window I can see peas, brussels sprouts, pumpkins, courgettes (zucchini), cardoons, marjoram, tiny bay trees and lemon balm mixed in with nasturtiums (of course), roses, rose of Sharon, aubretia, Corsican mint and primulas. I hope it helps to confuse the pests as well as being pleasing to the eye. (Well, mine anyway.) My "aha" moment was when I expanded my view instead of thinking of a yield in such a narrow way.