Companion Planting

Flowers are a nice addition to any garden. While many people might think of them as simply decorations,I make use of some of their other characteristics.These Nasturtiums for instance are edible and both the flowers and young leaves are a nice spicy addition to a salad.I plant them for the other benefit they bestow on my garden which is their ability to repel aphids, squash bugs, and most importantly, cabbage moths. I think they are very effective inter-planted in each row. Their biggest draw back is that they do not transplant well and the seed is expensive.
Another very decorative and useful, though not edible flower, is the common marigold. It definitely helps repel some of those harder to control type bugs such as cabbage moths and mexican bean beetles. Marigolds also are known to repel nematodes, a type of microscopic earth dwelling organism that can cause several  root diseases.
 There is a fairly long list of flowers as well as herbs that can help the organic grower in the everlasting battle with insects. The practice of inter planting for these characteristics is generally refered to as companion planting. To be effective, there must be a fairly dense population of the flowers.In my experience each flower will help protect those plants adjacent to them but the protection does not extend much beyond that. Still, once planted the flowers will not only brighten your garden, they will help protect it 24/7.