Milky spore is a bacterium that infects Japanese beetle grubs, a common vineyard pest, and keeps them from reaching the adult stage of life. Once a grub ingests milky spore, it will die in a matter of weeks and then its body will emit billions of milky spore bacteria. And the more the grubs eat, the more the milky spore is released into the soil. While it takes a few years for milky spore to become optimally effective, it will remain in the soil killing grubs for 20 years or more.
Use a nail to poke 15 holes in the plastic lid of your coffee can.
Fill the coffee can to 1 inch from the lip with milky spore powder. Seal the top by placing duct tape around the edges of the lid.
Apply the milky spore to the vineyard. Shake approximately 1 tbsp. of milky spore powder per 4 square feet of the soil's surface. Since Japanese beetle grubs attack the grape vine roots, concentrate your application to the area where the root systems spread.
Lightly water the soil 24 hours after you apply the milky spore powder.