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.
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.
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.
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.
- 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.
- 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.
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