The following article was taken from the Gardenville website. They are one of the original organic gardening suppliers, having started business in 1957.

Common differences, misconceptions and myths
of organic gardening programs.

Price

One of the most common misconceptions is that organic gardening costs more than synthetic. Although some organic products can be more expensive than their synthetic counterparts, in the long run an organic gardening program can save both time and money.

Rate of Return

Synthetic products create fast, temporary results. Your grass may become greener after an application of synthetic fertilizer, but a few months later another application will be required. Organic fertilizers are slow released, meaning they continue to feed your plants over time. This creates a long term, sustained green in lawns and healthier plants.

Selectivity

Although synthetic and organic fertilizers will both feed your lawn, organic fertilizers are not formulated to kill weeds. Synthetic weed & feed products are non-selective, so they don't just damage and kill weeds, but can also harm your desirable plants. Organic fertilizers can be spread through your entire landscape, without fear of harming the beautiful plants you worked so hard to maintain. Synthetic pesticide products will wipe out every insect in your yard and garden, including beneficial ones. Organic pesticides are designed to only attack unwanted pests, leaving valuable insects unharmed. Even worse, some chemicals found in synthetic products can cause harm to pets and humans.

Formulation

Organic products are created from naturally occurring materials. When reading the ingredients in an organic product, you can usually recognize the names. Synthetics are created using man-made materials and animal byproducts.
It is important to remember that "organic" does not always mean "safe". While an organic gardening program will generally be less harmful to the environment, pets and humans, it does not mean that products can be used irresponsibly. ALWAYS read the label of any product you purchase and follow all directions.