Plants get their nutrients from the air, water and soil. Non-mineral nutrients, such as hydrogen, oxygen and carbon, are obtained from the air and water. There are 13 mineral nutrients important to plant growth that come from the soil.
Plants use energy from the sun to change carbon dioxide and water into starches and sugar. The starches and sugars are the plant's food. This process is called photosynthesis. Sometimes there are not enough nutrients in the soil to grow healthy plants, so gardeners and farmers use fertilizers to add nutrients to the soil. The important nutrients that plants get from the soil are nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, iron, chloride, manganese, molybdenum and zinc. The texture and acidity of the soil determines what extent of nutrients are available to the plant.