Many herbs are considered attractants for beneficial insects that eat pest insects. So planting herbs is a great idea. We do that where I work. Also, planting marigolds as a companion plant is a good idea because they can help to ward off other pests as well. You often hear of people doing that in their vegetable gardens. For a source of good info on planting plants to attract beneficials as well as just good gardening info go to
Urban Harvest - Working With Gardens and Orchards to Build Healthy Communities.