The term organic fertilizer refers to materials that contain nutrients that are obtained from the byproducts or remains of an organism. Cottonseed meal, fish emulsion, manure, sewage sludge, and cottonseed meal are examples of organic fertilizers. These substances are naturally high in phosphorous, nitrogen, and potassium, which are the three chief nutrients required for plant growth. These types of fertilizer rely on microorganisms living in the soil to break them down so they can release these nutrients.

In contrast, chemical fertilizers are plant nutrients that are produced synthetically from inorganic materials. Many contain acids that can hard the soil's natural population of microorganisms. Because of this, they have the potential to stunt the growth of plants.

A major problem faced by the home gardener arises from nutrient deficiencies in the target soils. An advantage of chemical fertilizers over organic types is that they contain all three of the most important nutrients, phosphorous, potassium, and nitrogen. Organic fertilizers, on the other hand, either have high levels of one of these critical nutrients or low levels of all three.

Organic fertilizers are less expensive and more cost-effective than chemical fertilizers. Home gardeners can create their own organic fertilizers by combining manure from cows, sheep or poultry with other organic matter. They can tailor the mixtures to their own specific needs. Chemical fertilizers must be purchased from gardening stores or horticulturists.

A distinct feature of organic fertilizer is that it releases its nutrients slowly. This can be both beneficial and potentially harmful to plants. While the slow release of nutrients reduces the risks of over-fertilization, it may also mean that if there is a need for immediately nutrition, the organic fertilizer would not provide the level of nutrients needed. Chemical fertilizers are able to provide plans with an immediate supply of the necessary nutrients when circumstances require this.

A number of chemical fertilizers are high in acids. Acids in chemical fertilizers, including sulfuric and hydrochloric acids, result in high soil acidity levels. These destroy nitrogen-fixing bacteria, the microorganisms that are important for supplying the nitrogen needed for plant growth.

Plants don't know the difference between organic and chemical fertilizers, and their roots will absorb the required nutrients wherever they come from. However, in the light of increasing worries about the environment overall, the use of chemical fertilizers as a source of plant nutrients is being strongly questioned.