How to Get Rid of Lawn Grubs

Lawn grubs are pale white, squirmy larvae that can destroy your lawn from the ground up, munching on roots until your grass dies off. These pests are a natural part of the ecosystem, so if you just have a few, there’s no need to worry. However, if you’re finding a lot of grubs, you need to eliminate them immediately to avoid damage to your lawn.

Lawn grubs are the wriggly, worm-like larvae of different types of beetles, like Japanese Beetles and June Bugs, that hatch in the spring and summer. These pests are roughly an inch long, curl up into a C-shape when disturbed, burrow into your lawn, and feed on your grassroots. In small quantities, they’re fine, but if large populations are left unchecked, they can do serious damage.

The first sign of lawn grubs is often irregular brown patches in your lawn. These could be caused by many different factors, but if you can pull up the grass easily, it’s a clear indicator—the grubs will have chewed through the roots, making it easy to separate from the soil.

Increased animal activity is another sign. Grubs make up a large part of the diets of skunks, raccoons, and birds. If you notice a lot more holes in your lawn from digging or pecking, these critters might be after abundant grubs.

Testing your soil

Performing a soil test is a surefire way to tell if you have too many grubs. Start by removing a square foot of sod or grass, roughly two to three inches deep, from a dry, brown area. It’s likely you’ll find some grubs, and that’s not a bad thing. Here are the guidelines.

• Five or fewer grubs: There’s no need to worry, and no treatment is necessary.
• Between five and 10 grubs: This is slightly concerning, but you’ll only need to treat your lawn if your grass is unhealthy.
• More than 10 grubs: The infestation is serious and you should take action right away.

You can pursue two organic options for getting rid of lawn grubs before turning to chemicals. These are safer for the environment and won’t harm beneficial insects, but they will take longer to be effective. In some cases, it may take years for the natural treatments to fully eradicate a lawn grub colony.

Beneficial nematodes

These are naturally occurring microscopic parasitic worms that invade grubs, releasing bacteria until they completely kill off the host. This method is very effective, but it can take up to three years for full results.

The best time to apply beneficial nematodes is in the afternoon. You should water thoroughly before and after the application. Garden stores, nurseries, catalogs, and even websites sell beneficial nematodes. Be sure to use them soon after you receive them—they are living beings, and you don’t want them to die off before they can do their job.

Milky spore

This bacterium won’t harm you but is deadly to Japanese Beetle grubs. Simply sprinkle the powder onto your lawn to eliminate the grub population. Like beneficial nematodes, this approach can take several years to eradicate your grub infestation.

Drying out your lawn

This tactic may sound risky, but it will work. You can make your lawn inhospitable to grubs by not watering your lawn for three weeks to a month to dry out your soil. The eggs need moisture to survive and hatch later on, and they will die without it. You may be worried about intentionally drying out your grass, but most types will bounce back and re-green after a brief dry spell.

Chemical control is sure to kill off your lawn grubs, but it comes at a cost—using these treatments can kill beneficial insects, too. There are two types of chemical treatments.

1. Curative: These eliminate existing larvae. You’ll need to water your lawn before and after you apply a curative pesticide to make sure it gets soaked up by the soil. The most common curatives include the ingredients carbaryl and trichlorfon. Different curatives may kill grubs at different stages, so the time of year you apply them may differ. Always read the instructions before applying this type of chemical treatment.
2. Preventive: These products will help prevent future generations of grubs from taking over. You’ll find these sold as Merit and Mach 2.

Keeping your lawn healthy is your greatest weapon in the battle against grubs. Beetles don’t like to lay eggs in thick, tall, healthy grass, so keep your lawn well-fed, mow high, and don’t overwater.

TruGreen offers extensive Grub Prevention & Control Services. A specialist will use a pre-emptive application to eliminate white grubs before they can do too much damage. The specialist will start by monitoring the lawn for adult beetle activity, then apply insect control just before the hatching season. The product will get absorbed by the soil and stay in the root system to eradicate grubs that hatch.

The This Old House Reviews Team backs up our pest control recommendations with a detailed rating methodology that we use to objectively score each provider. We review pest control plans, navigate the provider website, speak with customer service representatives by phone and online chat (if available), request quotes, and analyze customer reviews for each provider. We then score the provider against our review standards for plan options, additional benefits and convenience factors, availability, trustworthiness, and customer service to arrive at a final score out of 100.

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