Kills the grub stage of the Japanese Beetle. Natural bacteria eats the grub from the inside. Safe for use around waterways. Milky Spores don't die, they just multiply and accumulate in the soil lasting for years and the benefits are guaranteed for 10 years. Milky Spore is organic. Just one spore consumed by a grub will multiply into 3 billion new spores when the grub dies. Apply anytime the ground is not frozen. Not harmful to man, animals or the environment. Does not harm beneficial insects.