Working with nature helps obtain a balance in the garden.  Planting flowers, alliums and herbs next to food crops disrupt the searching pattern of the pest looking for host plants.  

Simple steps like separating rows of cabbages, broccoli or other brassicas with rows of onions or sage is an excellent way to help protect from the cabbage looper.  French marigolds reduce the number of soil nematodes when the plant is turned back into the soil at the end of the season. Marigolds are also useful in deterring whitefly from entering greenhouses. Tansy helps repel ants and aphids.  Lavender is a general insect repellent and attracts bees and numerous butterflies.  Nasturtiums also have been effective in controlling aphids.  Plant nasturtiums around the base of tomatoes to deter the beet leaf hopper which can infect tomatoes with curly leaf virus.   Yarrow and hyssop plants attract hoverflies, which lay the eggs around these plants and when they hatch, their larval stage of the insect will begin to eat adult aphids.  Calendula flowers attract beneficial insect like ladybugs, hoverflies and lacewings, which love to feast on aphids.  Calendula flowers also have a sticky substance on their stems and foliage which traps whiteflies and aphids. 

What works in one area does not always work in another, so experimentation is the key to success.  Planting flowers and herbs not only add great benefits to the garden, but also color and interest to the garden landscape.