Beauty and flavor, working together
Many gardeners have discovered the advantages of growing flowers and herbs in their vegetable gardens. Not only does it add color and beauty, but many flowers and herbs can help protect your vegetables from insect pests and make your crops even more productive.
A lot of vegetables don't have particularly showy flowers, so to assist in attracting bees and other pollinators to your garden, interplant flowers with high nectar concentrations and/or ones that have blooms in shades of yellow, white, or blue (colors especially attractive to pollinators). Some plants good for this include sunflowers, sweet peas, zinnias, cosmos, and mints.
Certain insects, such as ladybugs and lacewings (which prey on aphids and other harmful insect pests) and ground beetles (which help eliminate slugs, snails, potato beetles, and cutworms) are very beneficial to your garden, and there are specific plants that attract them. To bring these little garden helpers to your crops, try planting parsley, coriander (the seeds of cilantro), or dill, or flowers from the aster family.
There are also several flowers and herbs that help to repel pest insects: Pot Marigolds (Asparagus Beetles), Geraniums (Japanese Beetles), Anise Hyssop (Cabbage Moths), Borage (Tomato Hornworm), Catmint (Aphids, Colorado Potato Beetles, and Squash Bugs), and Sage (Cabbage Moths and Carrot Rust Flies).
Another good way to use flowers as beneficial companions to your vegetable crops is to plant a trap crop. This is often done by surrounding crops of varies vegetables with something else that will draw the harmful insects, these sacrificial plants eventually being pulled and thrown away. Nasturtiums are commonly used as an attractive trap crop, attracting aphids to themselves and keeping them from your crops. Nicotiana is another good trap crop.
Another advantage of planting flowers with your vegetables is that you can place your cutting garden somewhere that design is not an issue. You can grow your favorite Celosias, Zinnias, Black-eyed Susans, and Salvias in straight, easy-to-cut rows or interplant them with your vegetables in a manner that's best for your crops as opposed to how they look.