Integrated Pest Management
An integrated pest management (IPM) program uses the least toxic pest controls first, instead of broad-spectrum chemical controls. IPM practitioners use careful plant selection, insecticidal soaps, horticultural oils, bacterial controls and beneficial predatory insects to control unwanted species. IPM has proven to be a highly effective means of controlling all kinds of plant pests, including those that attack turf grass, perennials and vegetables, while minimizing the impact on the environment.
If a plant is showing signs of insect damage, closely inspect the leaves and stems to determine the extent of the damage. Sometimes you may be able to use soapy water (a bucket of warm water with a bit of dishwashing soap) to physically wipe the destructive pests off the foliage. If this process doesn't work or the plant is too far gone to save, remove the plant, roots and all, from the garden. Don't put it in the compost bin where the pests can move to another spot in your garden; instead throw it away in the trash.
Before you spray – sometimes a small infestation will be only a minor problem, ultimately having little to no effect on the plant as a whole. Instead of using a chemical pesticide to treat the problem, prune away the affected plant part to prevent the pest from spreading to the rest of the plant. Keep an eye on the plant to see if any further damage occurs.
Careful Plant Selection
When possible, avoid planting plants that are known for attracting pests or are heavy chemical users. This prevents the problem from occurring in the first place. Use alternative plants that offer similar landscape qualities but are more suitable for your climate and don't have as many, or any, pest problems. For example, plant disease- and pest-resistant shrub roses instead of hybrid tea roses.
Beneficial bugs, such as praying mantis and assassin bugs, are those that eat the bad insect pests that chew on garden plants and kill or damage them. They're available through online gardening sources, garden catalogs, nurseries and garden centers. Often nurseries and garden centers sell empty boxes that come with ordering and shipping instructions as well as information on preferred release dates for your area.
One of the hardest-working beneficial insects is the ladybug. Ladybugs help to control aphids, various types of scale, certain mites and some whitefly larvae. To encourage newly introduced ladybugs to stay in a home garden, spray plants with water before releasing the beetles. A water-soluble insect "power" food that attracts the ladybugs may be sprayed directly onto the plant as well.
Another beneficial insect, similar to the ladybug, is the Cryptolaemus. When Cryptolaemus begin to hatch, they feast on mealybug eggs and adult mealybugs.
Keep in mind that if you use pesticides in your garden, you'll kill both beneficial insects and the harmful ones. So when you use insecticides, spray only the infested plants, and mix only the amount of spray that you need at that time. When using pesticides of any sort, always read and follow package instructions carefully.
Insecticidal soaps can be effective low-toxicity pesticides, but they kill insects indiscriminately. Dormant oils smother insects as they overwinter on trees and shrubs. The bacterium Bacillus thuringiensis, or Bt, is an effective treatment against caterpillars, such as tobacco bud worm and geranium bud worm. But butterflies begin life as caterpillars too, so in order to avoid killing them, spray only the affected plants, and mix no more than you'll use at one time.