- 1). Use a spade shovel to lift up 1 to 3 inches of grass and soil in a 1-foot-square area to see if you have grubs in early September. Areas to check are where grass appears to be dying and turning brown. Because there are other reasons that grass turns brown, you should always check the soil for grubs before treating the lawn. If you see the white C-shaped grub, you should treat the lawn in fall.
- 2). Purchase milky spore disease to apply to the lawn in fall. Milky spore is consumed by the white grub. After the grub dies and decays, the spores multiply and are released back into the soil. One application of milky spore can last for 10 or more years in the lawn. It is safe for the environment and safe for pets and wildlife. Products that contain halofenozide and imidacloprid cannot be used in the fall to control grubs.
- 3). Apply 1 tsp. of milky spore to the affected parts of the lawn where you have discovered grubs. Water the grass lightly so the milky spore soaks into the grass. If the area of grub infestation covers most of the lawn, a more widespread application is required.
- 4). If grubs infest most of the lawn, apply milky spores in rows four feet apart from each other. In the first row, apply 1 tsp. of milky spore every four feet. Start the second row four feet over from the first row. Apply the milky spore every four feet in that row. Continue making rows and applying 1 tsp. of milky spore. Water the grass lightly so the spores soak into the ground.
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