Grubs are the larvae of various beetles, such as Japanese beetles, June bugs, or European chafer beetles. They resemble plump, C-shaped creatures with soft bodies and voracious appetites — and they love to feast on grass roots, causing significant damage to your lawn if left unchecked.

Grubs might seem like innocent critters, but their munching habits can turn your once-luscious lawn into a battlefield. As these hungry larvae feast on grass roots, they weaken the foundation of your turf, making it more susceptible to drought, disease, and other pests. Let’s take a look at how to tell if your grass is affected by grubs, what to do about it, and how to prevent an infiltration from happening in the first place.
One of the easiest ways to tell if you have a grub problem is if critters like raccoons, birds, and even skunks start frequenting your yard more often. These animals love to devour grubs, so their presence is often a telltale sign of infestation.
Another telltale sign is if your grass begins to wilt and develop scattered brown patches. While this isn’t always an indication of grubs, a good way to find out is by grabbing a fistful of brown grass and peeling it up. If the grass stays put, there’s likely another problem at play; if it easily peels upward, grubs are probably the culprit — as they feed on the roots holding that grass in place. If you determine you do have an infestation, quick action is needed.
The first thing to do is assess the extent of the infestation. Dig small areas of your lawn using a spade or trowel to examine the soil. If you find more than ten grubs per square foot, it’s time to take action.
One approach is to use natural predators. Milky spore, a bacterium that specifically targets Japanese beetle grubs, can be applied to your lawn to help stop an infestation in its tracks. Another option is beneficial nematodes, which are available at most garden centers. These microscopic roundworms can be applied using a watering can or sprayer and are often quite effective against grubs.
If the infestation is severe or other methods haven’t worked, you may need to turn to chemical controls. Look for products specifically designed to target grubs in lawn areas and follow the instructions carefully — some products have specific application windows that affect their effectiveness. While these methods can tackle an active infestation, prevention is still your best long-term strategy.

One of the most important things you can do to keep grubs away is ensure your soil is well-drained and aerated, as grubs thrive in compacted soil. Regularly fertilizing and maintaining proper watering practices will keep your grass strong and resilient — healthy turf simply doesn’t make as inviting a home for pests.
Grubs also love to hide in tall grass and thatch, so keep your lawn well-maintained. Regular mowing at the appropriate height discourages grubs from settling in, and removing excessive thatch eliminates the cozy shelter these troublemakers depend on.
Finally, consider using a preventive grub treatment between late spring and midsummer, while grubs are still in their vulnerable early larval stage. This is the ideal window to stop them before they have a chance to establish themselves and do real damage to your lawn.