COMPANION PLANTING
Companion planting is a technique that uses the relationships between plants to allow plants to grow more easily.
The physical interaction of plants is the most apparent benefit of companion planting. The physical traits of each plant complement one another and lead to healthier plants. In nurse cropping, one plant is planted next to another to keep weeds out. Oats, for instance, are often planted along with hay. The oats crowd out weeds that would normally steal the nutrients that the hay needs to survive. However, the oats do not take nutrients and can be harvested along with the hay. In this case, the physical relationship between the hay and the oats results in a strong crop yield with fewer weeds.
The other type of relationship used in companion planting is chemical interaction. In this case, the chemical traits of one plant can be used to benefit other plants in the area. For example, legumes - plants such as beans and peas - can take nitrogen out of the air and put it into the soil for their benefit. This process helps other plants, too. Other plants can use the nitrogen brought into the soil by; the legumes. In another case of chemical interaction, the African marigold can be planted in gardens. The marigold releases a chemical into the air that keeps pests away and serves to protect other plants in the area.