Several insect pests, like aphids, mealybugs and scales, can attack your indoor plant collection and cause your houseplants to wilt, turn brown and die. Before resorting to commercially prepared, chemical-based insecticides, mix your own homemade insecticidal soap spray. This gentler approach can effectively kill most types of soft-bodied insect pests without toxic chemicals, according to North Dakota State University.
Fill a spray bottle with a quart of water.
Add a tablespoon of liquid dish soap. This creates a soap concentration that's strong enough to kill pests without harming your houseplants, according to Iowa State University.
Close the spray bottle and shake it vigorously to mix its contents.
Spray the solution onto your indoor plants, focusing on areas that are troubled with insect pests. Apply enough of the soapy water to thoroughly moisten the plant's surfaces, but not so much as to cause runoff.