Neither houseplants nor garden plants are immune to insect problems. A common pest both indoors and out is the aphid, for example, which colonize on the underside of plant leaves. Feeding on the leaves, they produce a sticky substance that often attracts ants and other pests. Aphids also spread disease as they move from plant to plant and can compromise an entire garden. Insecticidal soaps, ones you can make yourself, are an effective, no-chemical means to controlling these pests.
Mix 3 tbsps.liquid dishwashing soap with 1 gallon of water. Avoid antibacterial soaps or those that contain degreasers.
Pour the solution into a spray bottle and pour slowly to prevent bubbling and foaming.
Water the plants two to four hours after applying the soap. Rinse the soap off the leaves as you water to prevent scum build-up, which can inhibit leaf respiration.
Treat the plants daily until the pest problem is controlled. Continue to inspect the plants for pests regularly throughout the gardening season and resume using insecticidal soap if the insects reappear.