Humans require certain nutrients from food. Similarly, plants require specific nutrients in order to thrive. Unlike humans, plants cannot simply take a daily vitamin, but instead depend on their caretakers to provide the necessary nutrients for survival. Fertilizers contain the necessary nutrients for plants to reach their full potential and have a long, healthy life.
Fertilizer replenishes the soil. As plants grow and mature, they take in a soil's nutrients along with water. Over time, the nutrients become depleted. As this happens, plants become sickly and are unable to produce new foliage or fruit. In general, plants take 16 different nutrients from the soil, including magnesium, nitrogen, potassium, iron and zinc. Certain plants, such as citrus, require higher amounts of specific elements. In the case of these plants, customized fertilizer formulas are available.
Inorganic fertilizers are chemical combinations of various nutrients that the plants require. Inorganic fertilizers are typically mixed with water and absorbed instantly into a plant's root system. While inorganic fertilizers provide an excellent, fast source of nutrients, it typically cannot be used on young plants, as the chemicals can burn the root system.
Organic fertilizers are made entirely of plant and animal-based components. Examples of organic fertilizers include compost, bone meal, animal manures and wood ash. Organic fertilizers naturally contain all of the required nutrients for healthy plants, without the danger of chemical burns. Organic fertilizers break down slower than chemical fertilizers, so it is recommended that they be applied two to three months before planting to optimize the nutrients.
When to Fertilize
Organic fertilizers should initially be applied before planting. Most plants require fertilization at least two times every year--once at the beginning of a growing season and once after harvesting. Citrus and fruit plants fair best when fertilized four times each year to ensure the plant has adequate nutrition for every step of its annual development. Finally, grasses such as turfs require fertilization once each month during the growing season. Once the growing season has ended and the grass is dormant, it no longer requires fertilizer.
Fertilizer provides greener, healthier plants. Some fertilizers also contain anti-fungal and disease components to further benefit the plants. If you follow the instructions carefully, fertilizers are purely advantageous to any home garden, and the results are generally evident fairly quickly.