Why the onions are important in the holes?

Onions are important in holes when planting certain crops because they act as natural pest repellents. Onions contain sulfur compounds that deter pests like aphids, carrot flies, and cabbage worms. By planting onions in the same holes as other crops, you can help protect them from potential insect damage, reducing the need for chemical pesticides. Additionally, onions can also help improve soil health by adding organic matter and nutrients as they decompose.