Identify and Manage Grub Infestations in Your Lawn with Simple Tests

Brown patches on a seemingly healthy lawn can result from drought, pet urine, disease, excess fertilizer, or pests, yet many owners jump to the conclusion that grubs are responsible. The article advises a straightforward diagnostic: excavate a 12-inch-square section of the affected area to a depth of 3-4 inches and examine the soil for shrimp-shaped, half-inch to 1-inch larvae. A count below ten per square foot is considered normal and does not warrant treatment.

If ten or more grubs are found, the lawn may be severely damaged and should be addressed in late summer when the insects are most vulnerable. Options include milky spore powder, which targets Japanese beetle grubs but works best in warm climates, and beneficial nematodes, especially the Heterorhabditis bacteriophora strain, which infect and kill a range of grub species. Prior irrigation helps the biological agents work, and chemical pesticides are discouraged because they can harm earthworms, pollinators, pets, and humans. The guidance is authored by gardening columnist Jessica Damiano of one outlet.