Know your insect enemies. Part of being an environmental gardener is getting to know which insects are really a problem in your garden and knowing how to control them. Pests of ornamentals may be divided into two groups by the way they feed. Insects with chewing mouth-parts bite off and swallow portions of plants. They may eat the leaves or flowers, bore into the stems, or feed on roots.
Examples are caterpillars, beetles and grasshoppers.
Examples of these types of pests are aphids, whiteflies, scale, and spider mites. There are several ways to control pests. The mechanical way by hand picking, pruning, or spraying with a strong stream of water should be the first choice. Using natural enemies such as lady bugs and mantids work best in an enclosed area. Only when insect populations are threatening the life or health of your plants should you use chemical treatments.