Diatomaceous earth is composed of the preserved bodies of millions upon millions of tiny single-celled animals called diatoms, that lived in the warm oceans millions of years ago. As these tiny creatures died, their bodies drifted to the ocean floor by the billions, forming the layers of diatomaceous earth that we mine today. Diatomaceous earth is used in swimming pool filters and it is also used to kill a wide range of common garden insects, including fleas, ants and termites, cockroaches, and many more. In order to spread diatomaceous earth on your lawn you will need a dust spreader. These can be rented at most home improvement centers.
Spread your powdery diatomaceous earth on a dry and windless day. Do not water the lawn the day before spreading and wait until all dew has dried before beginning to spread the white powder. Do not spray if rain is expected within the next 24 hours.
Put on your breathing mask, your eye goggles and your gloves. Open the compartment of the dust spreader and fill it with diatomaceous earth. You may use a cup of some sort to scoop the powdery earth out of the bag and into the spreader.
Pump up the dust spreader as per the manufacturer's instructions and pull the trigger. Dust will spew out the nozzle tip of the spreader. Keep the nozzle close to the ground and sweeping back and forth in front of you. Start at the foundation of the house and slowly back up, spraying the flowerbeds and lawn as you move further and further away from the house. Try to cover the grass and the soil with an even dusting of the white powder everywhere.
Keep children and animals off of the lawn for 24 hours. After one full day, sprinkle the yard to dampen the white powder. It is now safe for children and pets to return to the lawn.