Companion planting is a gardening technique that involves growing different plants together to enhance growth, deter pests, and improve overall garden health. Certain plants can benefit each other by providing shade, support, or nutrients, while others can repel harmful insects or attract beneficial ones. For example, tomatoes and basil are often planted together because basil can help improve the flavor of tomatoes and repel pests like aphids. This method promotes a more sustainable gardening approach, reducing the need for chemical fertilizers and pesticides while maximizing space and resources.