Select Plants that Don't Need Chemicals

Synthetic chemicals are appropriate for successful gardening only on rare occasions and then only on a very limited basis. Sustainable gardening practices do not include the use of synthetic chemicals.

Given that general approach, there are still some plant selection options that can help to minimize problems from pests and diseases.

A very good first step is to use California native plants. While these plants certainly support many kinds of wildlife, including insects that we regard as “pests,” but ecosystem also includes a variety of predators that limit the populations of insect herbivores.

A very good second step, then, is to make your garden a friendly environment for the predators of insect herbivores. This category includes many insects, birds, reptiles, amphibians, and mammals. This action is not a form of plant selection, to be sure, but it is relates to Integrated Pest Management (IPM), which is a broader approach to the avoidance of chemical.

Often, plants that occur in nature, referred to as the species of a certain plant genus, has evolved to resist or tolerate pests and diseases,. In contract, hybrid plants have other positive characteristics, e.g., large blooms, pleasant fragrance, attractive bloom color, etc., but less protection from pests and diseases. Selecting “species” plants can be another step away from the use of synthetic chemicals.

When you want your garden to include hybrid plants, select those that hybridizers have developed to be resistant to pests and diseases. The best way to find such plants is to read their labels in a garden center or their descriptions in a mail order catalog. Keep in mind, however, that those labels and descriptions are marketing messages: the most reliable information comes from direct experience in your own garden or the advice of other gardeners in your community.

Several diseases attack the tomato, which is one of the most popular garden plants. Hybridizers have developed several disease-resistant varieties. These labels or descriptions of these varieties typically include codes to indicate their disease resistance. Here are examples:


Disease Resistance


Verticillium wilt




Fusarium Wilt


Fusarium, races 1 & 2


Alternaria stem canker


Tobacco mosaic virus-resistant



When planting tomatoes a good practice is to select varieties that are disease resistant.