Companion plantings of some kind have been practised throughout agricultural history. Some of the earliest written documents on gardening discuss these relationships. Early settlers discovered American First Nations people were using an inter-planting scheme of corn-bean-squash that balanced the requirements of each crop for light, water, and nutrients. In the 1800ís, hemp (cannabis) was often planted around a cabbage field to keep away the white cabbage butterflies in Holland. In many parts of the world today, subsistence farmers and organic gardeners grow two or more crops simultaneously in a given area to achieve a certain benefit.
Companion planting is the practice of locating particular plants near one another because they enhance plant growth, discourage pests and diseases, or have some other beneficial effect. When selecting your companion plants consider more than which pests are deterred. Think about what each plant adds or takes away from the soil and what effect the proximity of strong herbs may have on the flavour of your vegetables. Avoid placing two heavy feeders or two shallow rooted plant types near each other.