To get rid of lawn grubs, treat the lawn with grub insecticide in late summer or early autumn when the grub eggs have likely all hatched. For the best results, use grub insecticides with the chemicals carbaryl and trichlorfon as active ingredients. Milky spore, botanical neem oil and beneficial nematodes are natural alternatives to chemical insecticides.
Carbaryl and trichlorfon are short-lived compounds that kill lawn grubs in all stages of life. These chemicals do not linger in the lawn and can be used the next season as a preventive measure to kill any lawn grub eggs laid on the lawn.
Milky spore, a bacterium, is incorporated into the lawn soil and consumed by the lawn grubs. The spores kill the grubs and are then reissued into the lawn when the grubs die and decompose. This cycle of spore release and grub death repeats until all grubs are dead.
Neem oil works best as a preventative treatment, inhibiting the hatching and growth of lawn grubs, but can also be used to kill infestations. Dilute neem oil with water and spray directly onto the lawn.
Beneficial nematodes are tiny worms that dwell in the soil of the lawn and release a bacterium that kills lawn grubs. Beneficial nematodes are a good long-term solution since they release this bacterium on a regular basis to keep the lawn grubs at bay.