Whether you have houseplants, container plants on the patio, plants grown for their beauty, vegetables to produce food for you family -- or all of these -- there are times when foliage needs washing. Dust and grime inside or pollen and dust on outside plants build up on the surface of the leaves over time, detracting from the plants' appearance and reducing their ability to perform photosynthesis. Keeping your plants clean improves their health and beauty. Although they can be cleaned with plain water, using dish soap provides the added benefit of working as an mild insecticide.
Mix 3 to 4 tablespoons of mild dish soap in a gallon of water to make a solution. Do not use automatic dish-washing liquid, grease-fighting soaps or laundry detergent for washing plants. Harsh formulas pose the risk of damaging your plants and may eat away the natural waxy covering on the leaves.
Dip small plants into the solution and swish them to wash the foliage. Many plant lovers give new purchases from the nursery a bath in soapy water to clean them and remove any possible insects, such as aphids. Washing newly purchased plants before adding them to your collection is a good preventative practice. Iowa State University cautions, though, that a buildup of soap residue can damage plants. Rinse the plant with plain water to remove soap residue after an hour or two if you suspect insect pests. Otherwise, rinse the plant right after washing it.
Wipe down the leaves of larger plants with the solution, using a soft cloth. Stroke the leaves gently to remove dust and grime. Oregon State University Extension recommends using two cloths, one in each hand, to clean both sides of the leaf at the same time. Repeat the procedure with clear water to remove traces of soap residue.