Plants need minerals to produce chlorophyll and go through photosynthesis, fight off diseases, produce fruit and leaves, and grow strong stems and branches. Certain minerals also support a plant's growth, seed production, root system and ability to become weather resistant.
Minerals such as iron, magnesium and phosphorous play key roles in a plant's ability to absorb and metabolize sunlight. Iron-deficient plants, for example, tend to have yellow leaves. Plants that don't get enough phosphorous can't produce chlorophyll, grow or effectively produce flowers and fruit. Plants that don't get enough phosphorous have weaker root systems than plants that do, while plants that don't get enough magnesium cannot generate new growth.
Potassium helps plants produce fruit and leaves. Most plants get potassium from the soil, fertilizer or compost. This mineral helps plants fend off diseases and also supports photosynthesis. Other nutrients such as copper and zinc support a plant's ability to reproduce and absorb other minerals.
Plants absorb calcium through their roots and use it to support stem and branch growth. Because acidic soils neutralize a plant's ability to absorb calcium, some gardeners add lime to the soil to increase its pH level. Without sulfur, a plant's ability to produce seeds and grow its root system is compromised. Sulfur also helps plants grow in cold climates and survive cold temperatures. Plants can absorb sulfur through the soil or from fertilizer.