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Insecticidal Soap: What is it and does it work?

Insect on PlantLooking for a way to get rid of pests on your plants, but avoid the toxic chemicals? Insecticidal soap might be just what you need.

Insecticidal soap is composed of potassium fatty acid soaps used to control plant pests. It was used regularly in the past by gardeners to protect their crops before poisonous pesticides become the popular choice later on. However, with safer gardening treatments becoming more widespread, insecticidal soaps are having a comeback. In order to avoid the use of toxic and stronger chemicals, gardeners are now opting for more natural ways to keep insects from disturbing their plants.

The soap eliminates the protective wax on the insect, causing them to lose a great amount of water and die. The insecticidal soap acts on contact. After the soap has dried, it leaves no residual effect. These soaps must be applied to the insect directly, and cover them fully.

These effective and safer soaps are used to control insects such as mealy bugs, sawfly larvae, thrips, whiteflies, aphids, lace bugs, spider mites, adelgids and leaf-hoppers. They’re not as effective on honey bees, ladybird beetle larvae or parasite wasps. Chewing insects, like caterpillars and beetles, also seem to escape the effects of insecticidal soap.

These less harmful soaps are certainly less toxic than the incredibly strong pesticides used by gardeners before, but can be dangerous to some plants if oil is in the soap spray. Before covering the insects you see with insecticidal soap, test it beforehand.

Take a small section of the plant, spray the soap on the leaves and wait one full day to see if there are any side effects. Examine the plant for any signs of leaf scorching, brown or yellow spotting, wrinkling or burned tips on your plants. Stop using the product if you see any damage. The sensitive plants tend to be cucumbers, gardenias, peas, ferns and beans.

To maximize effectiveness, spray the insecticidal soap in the early morning or early evening hours. Applying it when the dew covers your plants allows the soap to dry as slowly as possible. This provides maximum effectiveness.

If at all possible, don’t spray the insecticidal soap during the hottest parts of the afternoon when the spray dries much too quickly to be successful. Spray the insecticidal soap thoroughly on the plant, but not to the point of overflow.

Whether you purchase your insecticidal soap or make your own at home, you’ll be pleased to be rid of the pests who are destroying your beloved plants.

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