June, July and August are typically the best times of year to kill grub worms. Insecticides and other pest-control methods are most effective on immature grubs. While grubs can still be treated by mid-fall, treating for grubs during the mid to late summer often produces superior results.
Grubs are the larval stage of several types of beetle. Grub worms can cause damage to lawns and may attract unwanted wildlife if left untreated. Irregular brown patches of lawn that can be easily removed from soil is a common sign that grub worms may be present. Natural grub treatments, such as milky spore or neem oil, and lawn treatment products, such as Dylox, can be effective for treating a grub infestation.