Grubs can be eliminated by allowing grass to become dormant and using a spray made with water, onion, cayenne pepper and garlic. The mixture can be sprayed on the lawn once a week using a garden sprayer. The entire process of eliminating grubs may take up to several weeks.
Stop watering the lawn
Do not water the lawn during the hottest months of the year. July and August are typically the driest, hottest months in the United States when grubs thrive.
Apply the garlic spray
In a blender, mix 1 cup of water with 3 fresh, chopped cayenne peppers, a clove of garlic and a chopped onion until the ingredients form a smooth paste. Pour the paste into a container and allow it to steep for 24 hours before straining. Add the strained liquid to a gallon of water, then pour into a garden sprayer. Spray the lawn weekly to control grub populations. The lawn can be lightly watered directly after spraying to help the spray mixture reach the soil.
Begin regular lawn maintenance
If grass is allowed to go dormant during the summer to eliminate grubs, revive it with regular watering as the weather begins to cool during autumn.