DALY: Separating myths from facts about organic vegetable gardening

The Extension office frequently receives questions from residents regarding organic gardening. There seems to be considerable confusion on exactly what it is and what it is not. Basically, organic gardening is using a combination of methods and strategies to produce healthy plants based on a holistic view of the garden.

This view includes seeing the surrounding landscape and the soil organisms as part of on overall system in balance with nature. The practice of organic gardening tends to be labor intensive. It requires a thorough understanding of the ecological relationships among soil, plants, and other organisms in the garden. It also requires considerable thought and planning. Contrary to popular myth, organic gardening is not simply a method of pest control nor is it just gardening without the use of synthetic pesticides and fertilizers.

A long-term outlook with respect to soil preparation is required when gardening organically. The development of healthy fertile soil will help provide the plants with the necessary nutrients. Whether you have heavy clay or light sand, you can take steps to improve your soil quality and stimulate the growth of healthy plants. Organic gardeners use natural organic fertilizers and mineral amendments to improve the overall quality and fertility of the soil. Most synthetic fertilizers provide nutrients that are immediately available to the plant. However, they do not contribute to the overall health and long term fertility of the soil. Organic matter in the soil is important because it breaks down and releases nutrients for plants to utilize. It also improves the soil's water and nutrient-holding capacity in addition to providing a habitat for beneficial microorganisms. Organic matter in the soil can be increased by the addition of manure, topsoil, peat moss, compost and other suitable materials. Also, consider having your soil tested through the Extension office to determine its nutrient levels and pH.

One way to control pest problems is to choose a plant that has varieties with known resistance to diseases and insects. For example, some varieties of tomatoes have been bred to have resistance to Fusarium and Verticillium fungal diseases and to nematodes, a microscopic worm that attacks the roots. Look for varieties that have the letters VFN on the labels which shows the tomatoes have resistance to these diseases.

Remove and dispose of plants showing symptoms of diseases. Reduce the incidence of disease by keeping the leaves and stems of the plants as dry as possible. Use drip irrigation rather than watering overhead to reduce the amount of time plants remain wet and also to conserve water.

Pest control begins by purchasing healthy plants that are free of insects, diseases and are of good quality. Encourage beneficial insects, such as lady beetles, lacewings and certain species of wasps to stay in your garden. Certain herbaceous plants, such as dill, wild mustards, yarrow and others provide shelter and food for these beneficial organisms. They should be planted among your vegetables.

There are several organic pesticides available. Botanicals are plant-derived materials such as rotenone, pyrethrum, and Neem oil products. Microbial pesticides are formulated from microorganisms or their byproducts that control certain insect pests. An example is Dipel, which contains a species of bacteria that target certain caterpillar pests. Minerals, such as sulfur and copper, are the primary organic materials to control fungal and bacterial diseases. But remember, even if a product is considered to be organic, it is still a pesticide. Exercise caution when using them. Some organic pesticides are as toxic, or even more so, than many synthetic chemical pesticides.

Organic gardening has both its positives and negatives. Understanding the basics of this practice and what it involves will help you succeed in having healthy, productive plants.

Timothy Daly, MS, is an Agricultural and Natural Resource Extension Agent for the Gwinnett County Extension. He can be contacted by phone at 678-377-4010 or by email at timothy.daly@gwinnettcounty.com.