Lawn grubs are white, thick, C-shaped worms that feed off the roots of grass, killing patches of lawn. The grubs are the larvae of the Japanese beetle. Beetles lay their eggs in the grass, and the grubs live in and feed off of the grass until they grow into beetles. There are commercially available toxins that kill the grub worms, but these are harmful to the environment, pets and children. You can kill grubs in an eco-friendly way with a powder that kills grubs but leaves all other life healthy.
Purchase a container of milky spore disease powder. Milky spore targets grubs, and multiplies inside their dying bodies. When the grubs decompose, their tissues release thousands of other milky spores into the earth.
Mow your lawn, so that the grass is as short as possible before you treat the lawn. The shorter the grass, the easier it is for the powder to sink down into the soil.
Use a level teaspoon of milky spore powder in spots on the lawn. Space the teaspoon mounds so that they are 4 feet apart from one another in every direction. A 10-ounce container of milky spore powder treats 2,500 square feet of lawn.
Avoid applying milky spore powder to the lawn when the ground is frozen. The powder will not penetrate the earth when it is frozen solid, and the powder will be wasted.
Water lightly with a water hose by hand or with a water sprinkler. The spores will spread out naturally, and will eventually infest the entire yard. Milky spore disease powder does not harm vegetation, environment, humans, pets or beneficial insects. The powder will only affect grub worms. You will not need to reapply for several years; milky spore disease will live in the lawn for up to 15 years.