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How to Get Rid of Lawn Grubs

If grubs have invaded your lawn, you have both all-natural options and chemical treatments to get rid of them. We’ll show you how.

Damaged Lawn iStock

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.

This Old House has created a comprehensive guide to show you how to get rid of lawn grubs, covering organic options and chemical alternatives, as well as some handy prevention methods. If you'd like to get rid of the grubs without all the time and fuss, consider hiring a professional lawn care company. The This Old House Reviews Team recommends TruGreen, an industry leader with dedicated grub control. To get a free quote, call 1-866-817-2287 or fill out this easy form.

What Are Lawn Grubs?

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.

How To Tell If You Have Lawn Grubs

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.

Natural Ways to Get Rid of Lawn Grubs

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 Ways to Get Rid of Lawn Grubs

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.

Preventing Lawn Grubs

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.

Top Recommended Company for Grub Control

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.

This lawn care provider also offers five annual lawn care programs and additional a la carte services, so you can customize your treatment plan. To get a free quote, call 1-866-817-2287 or fill out this easy form.

Frequently Asked Questions

When should I treat my lawn for grubs?

You should treat for grubs in late spring through early summer.

How do I know if I have lawn grubs?

There may be some obvious signs, like irregular brown patches of grass. You can perform a simple soil test to see if you have lawn grubs. Pick up a square foot of soil or sod that’s roughly two to three inches deep, and inspect it for white, worm-like pests.

Why do I have grubs in my lawn?

Grubs are a natural part of the ecosystem, but some lawns are more prone to infestations than others. These pests find ryegrass very appealing.

How do I get rid of grubs in my lawn naturally?

You can rid your lawn of grubs naturally by using beneficial nematodes, applying milky spore, or drying out your grass.

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