Fertilizer is an essential aspect of promoting a healthy, vibrant plant. Fertilizer replenishes and supplements the nutrients that plants need to bloom, produce and thrive. Understanding the active ingredients in fertilizer and how they affect the plant’s growth will aide in its proper selection and application. Fertilizer should be selected according to the needs of the plant to ensure that the plant does not receive excessive amounts of nutrients it does not require.
Nitrogen is required for healthy plant growth and is one of the main active ingredients in fertilizer. Nitrogen, found in chlorophyll, promotes greener foliage and an overall healthy plant. Plants use nitrogen to assist in the capturing of sunlight and its conversion to energy. Plants that lack nitrogen will have difficulty completing the photosynthesis process and, hence, will lack the appropriate nutrients to thrive. Plant symptoms of nitrogen deficiencies include yellowing of the foliage and weakening of the overall plant structure. Yellowing will appear on mature foliage first, spreading from the base of the foliage toward the tip.
Plants use phosphorus to develop healthy root systems. Phosphorus stimulates the development and growth of roots and the development of seeds and blossoming of flowers. This, in turn, improves the plant’s overall ability to absorb water and nutrients and improves the plant's overall strength. Phosphorus-deficient plants will show signs with burnt-appearing foliage tips and a reddish-purple color.
Potassium improves the plant’s immune system while improving the plant's flowering and fruit development. This nutrient, working with other elements, also assists plants in building protein and completing photosynthesis. Plants with potassium deficiencies will have wilted foliage and be scorched.
Along with nitrogen, phosphorus and potassium, magnesium is an essential requirement for healthy and vibrant plants. An active fertilizer ingredient, magnesium is included in most fertilizers as a basic ingredient. Magnesium is an essential element that plants use to complete the photosynthesis process. Plants also use this element to increase its iron utilization and control its nutrient intake. Plants with magnesium deficiencies will appear pale green and lackluster. The plant’s foliage will begin to curl and redden. Early leaf drop will also occur.
Calcium works with the plant’s essential elements by counteracting unwanted elements and promoting the development of the plant’s cell wall structure. It is an essential element that also assists in the intake of nutrients through the root system. Calcium deficiencies in plants result in poorly developed and weakened cell structures. Terminal buds and roots will fail to develop and the foliage will appear small and distorted.
Iron is another essential element that plants require for healthy and vibrant growth. A combination of iron and other macronutrients assist the plant in transporting nutrients that are used for photosynthesis and respiration. Iron deficiencies in plants will initially cause yellowing around the tips of newly developed foliage. As the deficiency progresses, the edges will begin to brown and the symptoms will begin to appear on mature foliage.