Natural Pesticides for German Cockroaches

Boric Acid

• Boric acid is a white powder derived from boron and water. When properly used, it’s an effective way to kill German cockroaches. Boric acid powder sticks to the roach’s body when it walks through a treated area, and the cockroach swallows it when it’s grooming itself. This is a slow-acting insecticide and you probably won’t see a reduction in cockroach numbers for a week or more. Apply a very thin layer of boric acid to hiding places, including cracks and crevices under sinks, stoves, along baseboards, behind refrigerators and in electrical outlet and wall voids. The boric acid should be barely visible. Cockroaches avoid thick layers of boric acid. Keep children out of treated areas.

Diatomaceous Earth

• Diatomaceous earth is the fossilized remains of one-celled organisms. It kills German cockroaches by cutting their waxy exoskeleton when roaches walk over it, so they die from dehydration. Sprinkle it on cabinet tops, behind appliances and anywhere else roaches hide, but don’t place diatomaceous earth where children or pets might contact it. Since the dying insects are searching for water, you’ll probably see more roaches following treatment, but most of the roaches die within two weeks. Silica gel, which is finely ground sand or glass works, like diatomaceous earth.

Traps

• Traps won’t eliminate German cockroaches, but help reduce their numbers. Place sticky traps near the garbage, under the sink, behind the refrigerator and in the bathroom. Make your own trap by coating the inner lip of an empty jar with petroleum jelly and baiting the jar with a slice of bread soaked in beer. The beer-soaked bread attracts the cockroach, and the petroleum jelly keeps it from escaping the jar. Wrap the jar’s outside in a paper towel making it easier for cockroaches to climb up the side. Kill trapped roaches by pouring dishwashing detergent and hot water into the jar.

Other

• German cockroaches don’t like catnip because it contains nepetalactone. Make catnip sachets and leave them where roaches are active. Make catnip tea and spray it around baseboards and other hiding places. Vacuum roaches up with your vacuum cleaner. Seal the bag and take it outside when you’re through.