Organic gardening is the art and science of growing fruits, vegetables, flowers, herbs, and all plants in harmony with nature and without using synthetic chemicals.
Organic gardeners regard the soil as a living ecosystem that must be nourished and taken care of. The system starts with a focus on healthy soil, which supports healthy plants. When plants are strong, they are naturally disease and pest resistant. Rather than apply chemicals to cure disease and control pests as conventional growers must do, organic growers are oriented toward prevention through continuous soil improvements. It's a big difference in attitude: the chemical quick-fix vs. long-term soil building.
Organic horticulture (or organic gardening) is based on knowledge and techniques gathered over thousands of years. In general terms, organic horticulture involves natural processes, often taking place over extended periods of time, and a sustainable, holistic approach - while chemical-based horticulture focuses on immediate, isolated effects and reductionist strategies. Article on Wikipedia
Organic gardening isn't only about not using chemicals. It's a system, a way of life that includes the following basic practices:
“To cherish what remains of the Earth and to foster its renewal is our only legitimate hope of survival.” ~Wendell Berry
Organic gardeners work with the goal of nourishing and maintaining the soil for the long-term rather than using it for a quick, seasonal fix. Soil and water contamination is reduced significantly. Organic vegetables are free from toxic chemicals and healthier for us. Besides they taste better.