Don't fret if you see webbing on your houseplants. Your home is likely not infested with house spiders, but rather your plants are infested with spider mites. Don't take this lightly, though, because spider mites suck out the contents of leaf cells. When you notice spots on your leaves and they begin to die back, you have a serious problem on your hands. This problem is easy to fix, and you don't need to buy expensive pesticides to get rid of them. A trip to your kitchen or bathroom, and voila! You have all you need to kill spider mites.
Water the houseplant at least three or four hours before treating it for spider mites. Slowly pour the water around the houseplant on top of the soil until you see it drain out the bottom. Dump the drainage saucer of water to ensure that the soil does not remain soggy. A water-stressed plant is more likely to suffer injury from insecticides, even natural ones, than one that is well hydrated.
Mix 2 teaspoons of liquid dish or hand soap for every quart of water in a spray bottle. Use a stronger solution -- up to 2 1/2 tablespoons per quart of water -- if a previous, weaker solution proved ineffective.
Spray one or two leaves until both sides are wet, and in three or four hours, wash the soap off under running water or use a wet rag to wipe down the leaves. Choose leaves that are in an inconspicuous area for this test application.
Wait one or two days to ensure that the solution did not harm leaves. Proceed with the rest of the houseplant if it did not cause damage, spraying both sides of all leaves. Rinse the leaves in three or four hours to remove the soap residue.
Reapply the homemade soap spray in five or six days, increasing the dosage, if necessary. After three or four applications, all the spider mites should be dead.