What is Organic Fertilizer?


Organic fertilizers are nothing new, but the green movement has brought them to the forefront. Major fertilizer companies have also taken notice. There are now organic fertilizer choices for the lawn as well as all aspects of gardening. Organic gardeners still make most of their own fertilizing materials. Gardeners have become more aware of the environmental damage done by chemical herbicides and pesticides. Over time, organic methods will create an enhanced growing environment. Soil becomes healthy and diseases and deficiencies requiring chemical applications no longer exist.

Organic vs. Natural

Organic and natural fertilizers contain similar ingredients. They are both composed of plant and animal waste materials. The difference is that there must be proof of purity to be labeled organic. With raw materials such as manure, the proof must go back to the diet of the animal. If any chemical residues are found in the grass or the manure, it will be labeled natural, not organic. Chemical residues are from the use of pesticides and herbicides. It can takes years for some chemicals to break down in the soil. This is why organic farming can be a challenge. Once the right practices are begun and the soil is cleansed, then organic gardening can be quite simple.


Compost is the most popular organic fertilizer. Being a mixture of different ingredients, it can supply well-balanced nutrition to plants. Making compost also provides a way to deal with unwanted landscape debris. Compost is a mixture of decomposed organic materials from manure, grass clippings, yard debris and vegetable scraps. Rotted manure from cows, sheep and chickens can also be applied as a single fertilizer or made into manure tea. Packaged fast-acting organic fertilizers are becoming more common. Some target certain plants, such as turf grass. Many others are all-purpose fertilizers for a wide range of plant types.


Commercially produced fertilizers will list the ingredients. The labeling should include a three-part ratio (NPK) of numbers. Each number represents a major macro-nutrient. The first is nitrogen (N), the second phosphorus (P) and the third is for potassium (K). These are the three most important nutrients your plants will need. This allows you to choose a fertilizer that has the right proportions for certain plants. Plants also need trace minerals. When using a variety of organic materials, these minor nutrients are rarely a problem.


Raw organic materials need time to decompose. It might take a year for nutrients to be available to the plant. Manures must be cured for 1 year or they will be hot and can burn plants. Materials such as manure can be piled up while they cure. It is a good idea to cover them so rain will not leach out the nutrients. Composting is a process that causes decomposition to occur quicker. Some composted materials can be used in only a few months. While waiting, you can use purchased organic fertilizers to supply nutrients to your plants. These will work quickly, but not instantly like chemical fertilizers.


Organic fertilizers can be incorporated into the soil at planting time. They can also be applied around the base of plants as a top-dressing each year after that. Manure teas can be applied at any time. They are made by steeping cured manure in water for 1 month. The liquid is then used to water plants. This is a great application for container plants. Because they are more refined and concentrated, always apply commercial fertilizers according to label recommendations. Ingredients such as fish or blood meal can be attractive to dogs, so bury them below the soil surface. They can also repel deer, so you can leave them on the soil surface as a deterrent.

Soil Structure

Chemical fertilizers supply nutrients and then drain away. Organic fertilizers add bulk to the soil. This helps the soil absorb and retain moisture needed for plants. It will also loosen clay soil and hold together sandy soil. Organic materials encourage microbial activity, which breaks the soil down into fine humus. These materials also attract earthworms and other beneficial insects. The result is healthy, living soil.

Keywords: compost, nutrients, nitrogen, potassium, phosphorus

About this Author

Marci Degman has been a landscape designer and horticulture writer since 1997. She has an Associate of Applied Science in landscape technology and landscape design from Portland Community College. Degman writes a newspaper column for the "Hillsboro Argus" and radio tips for KUIK. Her teaching experience for Portland Community College has set the pace for her to write online instructional articles.