In this whole series on replacing existing landscaping with Vegetables and Edibles you might think you'd have to sacrifice beauty. Not only is this not the case, but many vegetable plants actually benefit from having certain companion flowers nearby. I recommend doing some research on what gardeners call "companion planting". Certain kinds of flowers will help repel bugs. For example marigolds have a scent that confuses aphids and can help keep your cole crops from getting slimed. Others are a benefit because they will help increase the humidity and provide shade to keep heat sensitive lettuces and herbs from bolting.
A prime example of companion planting for us last year was planting our basil plants right along side our tomatoes. We never seemed to be able to get our basil to grow big and healthy. We always planted all the basil together and it would dry out and go to seed quickly. Last year we had broad leaf basil all through the growing season and with a little strategic snipping of flower buds, it just kept on producing. The increased humidity and the shade from the tomatoes made all the difference. This year we'll do the same with out cilantro and italian parsley.
Here are some basic combinations that are beneficial and beautiful.
Carrots go: onions, garlic, leeks, shallots, chives. Garlic have very nice round blooms and the purple blooms of chives are stunning.
Cole Crops (broccoli, cabbage, etc.): Geraniums, dill, alliums (onions, shallots, garlic, etc), rosemary, nasturtium, borage.
Cucumbers: Nasturtiums, radishes, marigolds, sunflowers peas, beets, carrots, and Dill
Peppers: Tomatoes, geraniums, petunias.
Tomatoes: Basil, oregano, parsley, carrots, marigold, Alliums, celery, Geraniums, Petunias, Nasturtium, Borage
Other things to know:
Mints (including hyssop, sage, and various "balms") repel slugs.
Borage and Lovage go well with most things. Borage is pretty and east to grow.
Marigolds are an all around powerhouse in repeling aphids.
Put your Cilantro with spinach but not lettuce.
Fennel doesn't get along with anyone in the garden.
Most of the info here comes from this article on wikipedia.