Fertilizers are additives that are used to improve the quality of soil. The main ingredients in most fertilizers are nitrogen, phosphorus and potassium. The two main types of fertilizers are organic and inorganic. Fertilizers are usually added directly into the soil, but can also be sprayed on the leaves of plants or sprinkled on top of the soil.
Organic fertilizers are those that are naturally occurring. Compost is one type of organic fertilizer. It is made from recycled leaves, yard waste and household waste, such as potato peels and fruit rinds. Manure is another type of organic fertilizer. This type of fertilizer is high in nitrogen and is easily broken down into the soil, but is released very slowly. When organic fertilizer is used, it is usually supplemented with a chemical fertilizer.
Some fertilizers are specifically blended for different types of flowers and plants. Orchids have their own fertilizers, as they require a specific ratio of ingredients in order to gain proper nourishment. Plants that are especially sensitive require a certain blend of nutrients in order to avoid burning or over feeding.
Chemical fertilizers, or inorganic fertilizers, are manufactured and are generally cheaper than organic fertilizers. Most fertilizers that are used in gardens are chemical fertilizers. These fertilizers are water soluble and are usually activated with water. They do not drain off and include time-release varieties. It's easy to apply chemical fertilizers evenly so that the application is accurate.
Liquid fertilizers are often the best choice for potted or indoor plants. Liquid fertilizers get nutrients right to the plants through the roots. The liquid is absorbed directly into the plant's root system and dispersed immediately. These types of fertilizers are usually sold in small containers, and cost more than granulated fertilizers. They are not a cost effective choice for large areas.
Slow-release fertilizers are also referred to as time-release fertilizers. They can be either organic or inorganic. This type of fertilizer releases nutrients into the soil very slowly and can last up to six months. Slow-release fertilizers lower the risk of burning the plant because the plant does not receive a large initial does of fertilizer. Nitrogen is the most common ingredient in slow-release fertilizer.