Starting With Soil: Organic Garden Fertilizer

Successful organic gardening begins and ends with good soil. At the beginning and end of every growing season, the organic gardener works with the soil to make sure it will produce abundant organic produce and flowers. He or she adds organic garden fertilizers at least twice a year to enrich the soil and replace nutrients that the plants have used.

Organic garden fertilizers are not chemically manufactured. They are made from live materials. Organic gardeners also may add various organic or inorganic soil additives to control the pH or add micronutrients to the soil. Epsom salts and potash are common organic soil additives.

The difference between organic garden fertilizer and soil additives is like the difference between major nutrients and vitamins. Organic garden fertilizer improves the substance of the soil; soil additives may help improve the consistency or to provide micronutrients.

Animal-based Organic Garden Fertilizer

Most animal-based organic garden fertilizer can be reduced to one word: manure. There are other animal-based organic garden fertilizers, such as fish emulsion, but manure is the most commonly used. Chicken manure, bat guano and cow manure are favorites, but you can also use horse and rabbit manure. Even composted human manure is used in some places.

You cannot use manure from predator animals, such as cats. Their digestive systems contain bacteria that are pathogenic to humans, and the bacteria can get into or on food grown in soil fertilized with their feces. All manure should be aged or composted before using it as an organic garden fertilizer. This removes E. coli and other potentially dangerous pathogens. Composted manure can be added to the soil in either a solid or liquid form, and should be well mixed into the soil. Manure should be added to the soil at least several weeks before planting to allow it to age and mix with the soil—and to make the gardening experience more pleasant.

Plant-based Organic Garden Fertilizer

Seaweed, compost, worm castings and "green manure" are the most common plant-based organic garden fertilizers. Seaweed and kelp are usually purchased as dried and processed organic garden fertilizer.

Making compost for organic garden fertilizer is an ongoing process. You can learn how to do it from community workshops or other experts. It is an excellent way to recycle vegetable matter, such as peelings and scraps.

Worm castings, or worm composting, are very rich in nutrients and can be either purchased or made. To create worm castings, you need the right kind of worms, which you can get from any organic gardening source, a covered tub of some kind, and slightly damp vegetable matter. Even old newspapers will do. The worms do all the work, and you get rich organic garden fertilizer at almost no cost.

"Green manure" is planted as a cover crop, usually in the fall after harvest. You usually plant a nitrogen-fixing crop, such as soybeans. When the cover crop emerges in the spring, you dig it into the ground, allowing the plants to decompose and enrich the soil.

Whether you purchase organic garden fertilizer or make your own, you will be adding natural, living matter to the soil. You'll be preventing the chemical runoff that happens with chemical fertilizers. And you'll be enriching your soil, which is the source of life for your garden.