Increasingly, home gardeners are turning to using less or no synthetic fertilizers or soil amendments when growing fruits, vegetables and ornamentals.  In the last few years, the Master Gardener office began receiving many more calls from people inquiring about organic gardening, so it's no surprise that most large grocery stores now feature a separate organic produce section.  With all the increased concerns about food safety and contaminants in the soil, there are good reasons for growing the organic way. 

Just what does it mean to practice organic gardening?  If you want to advertise your produce as organic at a local farmers' market, for instance, you must be a "Certified Organic Grower" according to the strict guidelines of the U.S. Department of Agriculture.  If, however, you're just growing vegetables for your own use or giving away some to friends and relatives, organic gardening is something you can practice using "natural" soil preparation and fertilization methods, as well as weed, pest and disease control that consists of using no synthetic herbicides or pesticides. 

First, a good organic garden begins with good soil preparation.  You still need the three essential soil nutrients of nitrogen (N), phosphorus (P) and potassium (K), but you will be incorporating them into the soil differently than if using commercially-sold synthetic fertilizers.  The best way to get these nutrients into the soil in an organic garden is by amending the soil with compost.  You can either make this yourself using materials such as kitchen waste and lawn and plant clippings or buy bagged compost at any garden center or nursery.  These amendments not only add small amounts of the essential nutrients, but also improve soil texture so that its water-holding ability is increased.  Over time and with the continued addition of compost, even our heavy clay soils in El Dorado County will be greatly improved and your plants will develop stronger root systems and more vigorous foliage and fruit.  Other organic soil amendments such as bird guano or rock phosphate are labeled with the same N-P-K numbers as chemical fertilizers, so you can be sure you are providing essential nutrients for your plants, especially when you are first getting started with organic growing. 

Animal manure (except for that of cats and dogs) is an important soil amendment too, but a note of caution:  Fresh manure can burn plants, so it should be aged or put into a compost pile first before being added to the soil. 

As far as pest and disease control in an organic garden is concerned, a little more labor is required than just grabbing the nearest chemical spray.  Weeds should be hand-pulled and if you use a 3-4" layer of mulch in your garden, even weeds will become less and less of a problem.  Interplanting, or companion planting, and crop rotation are methods used in organic gardening to repel some pests as are attracting beneficials such as ladybugs into the garden.  Some sprays are organic such as compounds with the naturally-occurring bacterium, Bacillus thuringiensis (Bt) as their main ingredient; this is specifically formulated to kill caterpillars.  Another control method for caterpillars is simply to handpick them.  Soap sprays can be used on smaller insects such as aphids, but such sprays utilize a contact control method which means the spray must be applied to the specific target pest for control.  Even if you're using these less toxic control methods, always read and follow the label directions.