What Are Grubs and How Do I Control Them?

Grubs and their notorious below-ground destruction may go unnoticed until late summer. Learn how to control grubs before they damage your lawn.

Have you ever turned up a bunch of plump, white, c-shaped creatures while digging in your yard? Those were grubs, the larvae of Japanese beetles, June beetles, or chafers. You probably interrupted them mid-snack, as they have voracious appetites after hatching and like nothing better than to feast on organic matter in the soil—including your lawn's roots. Unfortunately, grubs and their notorious below-ground destruction may go unnoticed until late summer, when dead patches of grass suddenly appear in your lawn and begin to spread.

Signs of a Grub Problem

• Raccoons, skunks, armadillos, or birds dig up your yard searching for large, mature grubs to dine on.

• The dead patches of grass in your lawn peel back like pieces of loose carpet because the grubs have eaten the roots that usually hold the turf in place.

• Before dead patches even appear, your lawn feels spongy, like freshly laid sod, when you step on it.

The Life Cycle of a Grub

It's like the scene of a horticultural horror movie: Beetles emerge in early summer, feed on plants in your garden, then lay eggs in the soil in your lawn. Later in the summer, the eggs hatch and the grubs begin to eat. They continue to devour all of the grass roots they can reach, growing big and plump, until mid-fall, when they move deeper in the soil for protection against cold winter temperatures. When the soil warms up again in spring, the large, mature grubs move back into the upper soil levels, transform into adult beetles, and start the whole process over again.

How to Control Grubs

1. Time it Right

It's always easier to prevent a grub problem than to wait until the damage is done and you have to deal with an infestation. Get a jump on things by applying Roundup® For Lawns Bug Destroyer early in the spring or summer, before the grubs hatch.

2. Maintain Your Lawn

A properly maintained lawn can tolerate more grubs per square foot than a stressed lawn. A drought-stressed, underfed lawn, on the other hand, will show grub damage faster (even with fewer grubs per square foot) than a lawn that has been well cared for.