Organic Fertilizer

There are 4 main types of organic fertilizer. These are based on - plant, animal, mineral, and compost.

Most organic fertilizers are made up of a combination of organic materials from different sources, although some only have one 'ingredient'.

Organic Plant Fertilizers

A renewable source nutrient, organic plant fertilizers tend to be nitrogen rich. An example of a plant organic fertilizer is alfalfa meal - an organic fertilizer made of green manure crops. In addition to nitrogen, phosphorus, and potassium alfalfa meal also contains Triacontanol, which is a growth hormone for plants.

Cottonseed meal is another type of plant organic fertilizer. It contains 7% Nitrogen, 2% Phosphorus and 2% Potassium. With the high Nitrogen content, cottonseed meal is second only to blood meal in providing the most organic nitrogen to plants.

Plant organic fertilizers may also be made from seaweeds and algae. Organic fertilizers made from kelp meal contain very high potassium along with many trace elements. Seaweed fertilizer is a great source of growth regulating plant hormones. This type of organic fertilizer is excellent for greening the plant foliage and stimulating growth.

Organic Animal Fertilizers
Organic fertilizers are also produced from the by-products of animal processing. The dairy farming industry along with and meat and poultry processing plants produce materials that are a rich source of nutrients and minerals that can be utilized by plants. Organic fertilizers that come from animals include bone meal, blood meal and fish emulsion.

Blood meal is known to be the best source of quick-acting nitrogen. This type of organic fertilizer is completely soluble and applied when watering the soil.

Bone meal is an organic fertilizer that is rich in calcium, phosphorus, nitrogen and potassium. Bone meal organic fertilizer best suits young plants because it releases its nutrients extremely slowly.

Organic Mineral Fertilizers
Mineral-based organic fertilizers include rock phosphate, Chilean nitrate, sulfate of potash magnesia and green sand.

These fertilizers do produce vigorous growth in plants, particularly vegetables, but they also need to be applied regularly as their soluble nature means they quickly leach out of the soil if not taken up immediately by the plant. Compare this to compost which is incorporated into the soil and releases its nutrients over time.

Compost
Compost is the cheapest source of organic fertilizer - and many gardeners also consider it to be the best. Make your own in your backyard from compostable kitchen and household waste. Nutrient levels will vary depending on what has been composted - but they can also be controlled through the addition of specific materials.

Fish meal or fish emulsion is an organic fertilizer made entirely from finely ground fish parts that are rich in the trace elements - boron, calcium, phosphorus, potassium, magnesium - and are very beneficial to plants.

Some commercial companies add other ingredients into their branded fish based fertilizers including vitamins, amino acids, enzymes, growth hormones and nitrogen.

Seaweed is another source of natural organic fertilizer. Seaweed extract is an organic storehouse containing more than 60 nutrients and amino acids. Remember, if you live close by a beach and there are no local restrictions to prevent you harvesting your own seaweed, you can comb the beach after high tide to collect seaweed from the beach.

Wash the seaweed in clean water to remove salt residues and add to your composter or dig straight into the soil. The seaweed will break down very quickly releasing its nutrients for use by your plants.

Natural organic fertilizers may also come from crab shells. In addition to containing nutrients crab shell is also extremely effective at pest-control as it contains Chitin, the food source of chitin-eating bacteria that kills fungus and nematodes.

Why would we choose to use an organic garden fertilizer?

The answer is simple - it's good for your plants, good for you and good for the environment.

Organic garden fertilizers increase the nutrient content and soil characteristics of your garden. In organic gardens, the presence of decomposing organic matter acts as a natural organic garden fertilizer to supply plants with nutrients essential for their growth cycles.

Organic garden fertilizers also help improve and maintain structure of garden soil, regardless of type. With a clay based soil, organic garden fertilizers preserve the tilth and structure to prevent the soil from clumping. With finer, sandy soils, an organic fertilizer will increase and maintain the water-holding capacity of the soil.

By making your own compost you will be productively using materials that would otherwise have been discarded - you have your own recycling centre in your backyard.

Knowing which nutrients are contained within which fertiliser will help the gardener choose the most suitable product for his or her gardening needs.

There are three major nutrients that plants need in order to grow. - Nitrogen (N), Potassium (K) and Phosphorus (P). Because organic materials tend to be rich in single nutrients suppliers have developed blends by combining one or more base ingredients to increase the range of nutrients in the finished product. It is then up to the gardener to select the product containing the nutrient mix that best suits the plants being grown.

Alfalfa meal is a green manure-based organic garden fertilizer preferred by rose growers. With its 3N-1P-2K formulation, this organic garden fertilizer is an excellent source of nitrogen (N) and potassium (K) with a lower level of phosphorous (P).

Blood meal has a formulation of 12 (N) -2 (P) -1(K). A slaughterhouse by-product, this organic garden fertilizer is great source of quickly available organic nitrogen. If calcium and phosphorous are required is can be mixed with bone meal organic garden fertilizer.

Kelp meal has very high potassium content and zero phosphorus. To compensate, this organic garden fertilizer is often used in conjunction with bone meals.

All organic garden fertilizers are not created equal. They can contain several micronutrients but may also lack several of them. The trick is to know how to read the ingredients so you know what's in the bag.