How to Get Rid of Grubs in Your Lawn

white yard grub laying in a c-shape in soil

Is your lawn turning brown? Grubs might be the cause. They eat grass roots, which means the grass can’t absorb water from the soil. If you want to save your landscape, you have to learn how to get rid of grubs in your lawn.

These white grubs or lawn grubs are the larvae of different types of scarab beetles, such as Japanese beetles, European chafers, or June bugs. They emerge from underground and feed in spring and early fall.

How to get rid of grubs in your lawn

Homeowners are happy when they have a lush, green lawn. But if lawn grubs are lurking beneath the surface, these small, C-shaped larvae of various beetles can wreak havoc on your otherwise beautiful turfgrass.

Let’s go over the steps to identify and control grubs, preventing them from turning your lawn into their everyday feast.

Step 1: Identify your grub problem

The first step to treating a grub problem is identifying it. Other problems, such as drought stress, lawn diseases, and other pests cause brown patches that look similar to grub damage. So, confirm that it’s really grubs you’re dealing with before investing time and money in treatments.

Even though there are thousands of species of grubs, they all look pretty much the same to the untrained eye. Here are their most common characteristics:

  • Size: ⅜ inch to 1 inch, depending on the species
  • Shape: Worm-like bodies with three pairs of legs near the head; often curl into a C-shape when exposed
  • Color: Milky white body with a brown head
close-up of a white grub with a brown head

Signs of grub damage in your lawn

Grubs cause damage by eating the roots of your grass and, sometimes, even small plants. The following signs indicate grubs are invading your lawn:

  • Yellowing grass that turns into brown patches
  • Grass that pulls out of the soil easily
  • Loose soil and dead patches of grass
  • Grass that feels spongy when you walk on it
  • More animals (such as birds, skunks, and raccoons) in your yard than normal, and holes in the ground due to their pecking or digging

How to test your soil for grubs

The best way to be sure you’re dealing with lawn grubs is to see them with your own eyes. But these larvae live in the soil, so you have to do a little work before you can see them.

Grub soil test: Dig up a section of grass from the browning area about 1 square foot large and 2 to 3 inches deep. If you have grubs, you’ll see them. You’ll know you have an infestation if you see 10 or more in the square foot of exposed soil.

Step 2: Choose the grub control method

Once you’ve identified a grub infestation, you’ll need to decide how to tackle the problem. There are two primary approaches: chemical grub killers and natural methods.

Chemical grub control

Chemical insecticides you can buy from your local garden center are the most effective way to exterminate and prevent grubs in your lawn. However, they have significant downsides, as these chemicals:

  • Can hurt bees and other pollinators
  • Pollute groundwater, lakes, rivers, and other water sources
  • Can poison children or pets that come in contact with the chemical or treated area
  • Reduce populations of insects that prey on lawn pests, potentially making your grub problem worse in the future

For these reasons, most homeowners use chemical pesticides as a last resort. So, you should only use them if your lawn problem is severe and you can’t get it under control with natural methods.

Curative pesticides for grubs

When you already have grubs in your lawn, you can use curative pesticides. These chemicals will wipe out any grubs they touch, but they don’t have any residual effects on future grubs. For best results, use pesticides with the active ingredients carbaryl or trichlorfon.

Best time to use curative pesticides: Use these pesticides only when you’re sure you have active grubs in your lawn. They’ll be most effective on grubs present during the months of August and September. Spring grubs are further along in their development and more resistant to pesticides.

Natural ways to get rid of grubs in your lawn

If you want to avoid chemical insecticides, here are some organic methods you can try first. The best time to try these methods is August through September – when newly hatched grubs are actively feeding on grass roots.

Beneficial nematodes
close-up of nematodes under a microscope
snickclunk | Flickr | CC BY 2.0

Beneficial nematodes are microscopic, living creatures that feed on grubs. Nematodes, such as Heterorhabditis bacteriophora and Steinernema feltiae, are a long-term solution because they reproduce on their own and continue feeding on grubs (and other pests) for years.

Milky spore

Milky spore is a bacterium that infects Japanese beetle grubs. It’s one of the oldest and most popular natural solutions to Japanese beetle grubs, but it requires patience. After you release the bacterium into your soil, it can take up to three years to work.

Note: Milky spore doesn’t work on all grubs, only Japanese beetles. Distinguishing between different species of grubs is extremely difficult. Only use milky spore if you’ve had Japanese beetles before and are certain that’s the kind in your lawn now.

Neem oil
3 glass containers full of yellow oil

There are two types of neem oil: raw neem oil, which contains the insecticide azadirachtin, and clarified hydrophobic neem oil, which has most of the azadirachtin removed. Clarified hydrophobic neem oil is usually the kind you’ll find in stores. You can use clarified hydrophobic neem oil to suffocate grubs in your soil.

Warning: Neem oil can damage plants, so be careful not to get any on your garden plants. The grass is hardier and usually won’t suffer damage. Also, neem oil can harm beneficial insects.

Lawn-aerating shoes

Yes, believe it or not, we mean the shoes that go on your feet. Lawn-aerating shoes are just like normal shoes but with spikes underneath. They’re meant to poke holes in the soil for lawn aeration, but you also can use them for grub control.

Note: This method may not solve large infestations. But if you have a small number of grubs in your garden, aerator shoes could be worth a try.

Attract birds to your yard
birds eating birdseed at a feeder

Many birds feed on grubs (and adult beetles, too). A grub infestation alone is often enough to attract birds, but you can attract even more if you set up birdhouses, feeders, and baths around your yard.

The more birds you can attract, the more they’ll decimate your lawn’s grub population. Plus, a large number of predators can deter more adult beetles from moving into your lawn and laying eggs in the future.

Step 3: Apply the grub treatment across your lawn

Grub killers come in different forms, such as liquid sprays and dry granules or dusts. Here’s how to apply the different forms to your lawn:

Dry pesticides

If you’re using a dry pesticide, do the following steps:

  • Step 1: Use a drop or broadcast spreader (a common lawn care tool you can find online or in garden supply stores).
  • Step 2: Read the pesticide label to find out how much of the product you should put in your spreader and what adjustment you should set the spreader to.
  • Step 3: Cover the entire lawn with the spreader. Do your best not to miss any spots.

Liquid pesticides

Here are the steps to follow if you’re using a liquid pesticide:

  • Step 1: You can use a hose sprayer to apply liquid pesticides. Some pesticides already come in a hose spray bottle, but if yours doesn’t, check the label for how much pesticide to put in the hose sprayer for the correct concentration.
  • Step 2: Attach the sprayer to the end of any standard garden hose.
  • Step 3: Spray the mixture of water and pesticide across your whole lawn. Try not to miss any spots or use so much that the liquid runs off into other areas.

Milky spore

If you’re using a lawn and garden dispenser tube, use a funnel to fill the dispenser. You will need a teaspoon of the powder for every 4 feet of lawn. Slowly pour the powder through the funnel into the top end of the tube.

But if you’re using a drop spreader for granules, park the spreader on a flat, even surface, ensure it’s dry, and fill the hopper with the granules.

Note: For best results, add milky spore to the lawn when the soil is between 60 and 70 degrees Fahrenheit. Also, since spore powder is lightweight, never use a broadcast spreader for applying it, as the wind will just blow it away.

Other grub killers

  • If you are using beneficial nematodes, remember that they are live organisms. So, you have to introduce them to the lawn soon after you purchase them. They love moisture, so water the lawn before and after application unless the ground is already wet from rain.
  • If you’re using neem oil, spray it on and around the brown patches in your lawn to suffocate grubs. You can either purchase a neem oil spray or mix one yourself with this recipe:
  • Mix ⅓ teaspoon of mild or natural soap (like Castile soap) into 1 quart of warm water. Shake well.
  • Add 1 teaspoon neem oil to the mixture and shake well again.
  • The method of using aerator shoes is quite simple. Wear the shoes and walk across your lawn a few times, concentrating on areas with brown patches. When the spikes poke into the soil, they should stab through at least some of the grubs in your lawn.

To ensure a successful application, remember to:

  • Overlap passes
  • Work in sections
  • Start at the perimeter
  • Cover the entire lawn
  • Keep the spread even
  • Maintain a steady pace
  • Pay extra attention to infested areas
  • Follow the recommended application rate
  • Keep records of your treatment schedule

Step 4: Water the lawn thoroughly

Watering is crucial to activate the chosen treatment and help it penetrate the soil. Depending on your chosen grub killer, you should give your lawn a thorough soaking immediately after applying the solution.

Step 5: Leave the treated area alone

Leave the treated area alone until it dries. Check the product label to find out when the area will be safe for children and pets.

For best results, avoid disturbing the treated area for a few days after applying the treatment. This allows the product to work effectively and minimize the risk of grubs escaping.

Step 6: Repeat application

Some grub control methods may require multiple applications to achieve the desired results. You can follow up with additional treatments if they are recommended on the product label or your chosen natural method’s instructions.

Pro tip: Following each application and thorough watering, it’s crucial to keenly monitor your lawn for shifts in grub activity and the general well-being of your grass. As time progresses, you should begin to witness a reduction in grub-related harm and a noticeable improvement in the overall health of your lawn.

How do grubs damage lawns?

The larval stage of various beetles might appear innocuous at first glance, but their presence in your lawn can wreak havoc on its health and appearance. Understanding how grubs damage lawns is essential in recognizing and addressing the issue effectively.

  • Root feeding: These voracious feeders primarily target grassroots as their primary source of nutrition. They chew through these vital structures, severing the connection between the grass and the soil. As they continue to consume roots, grass blades above ground begin to wither and brown.
  • Patchy, brown areas: One of the most noticeable signs of grub damage is the emergence of brown, irregularly shaped patches on your lawn. These areas are often mistaken for drought stress or other issues, but closer examination will reveal that the grassroots have been devoured by grubs, causing the turf to die off.
  • Weakened grass: As they continue to feed on grassroots, the grass becomes increasingly susceptible to other stressors. Environmental factors such as heat, drought, and cold weather can exacerbate the damage. Additionally, weakened grass is more susceptible to disease and invasion by other pests.
  • Thatch buildup: Their feeding habits can contribute to the buildup of thatch – the layer of dead grass clippings and other debris that builds up near the soil surface over time. Excessive thatch inhibits water and nutrient penetration, hindering the grass’s ability to grow and thrive.
  • Invasive animals: They can attract unwelcome visitors to your lawn. Animals like skunks, raccoons, and birds are known to dig up lawns in search of these larvae as a food source. This not only compounds the damage but also creates unsightly and disruptive disturbances.

When to look for grubs

For effective grub control, you have to understand the grub life cycle. Look out for damage from grubs in your lawn during spring and early fall. Here’s why.

Japanese beetle lifecycle illustration
Infographic by Juan Rodriguez

In April or May, full-grown grubs come up to the surface after spending the cold winter months deep underground. It’s difficult to treat spring grubs, even with chemicals, because they’re so large and developed.

Those grubs soon grow into adult beetles and fly away from the soil in mid-June. In hotter climates, this cycle may happen in mid-May. They lay eggs during this time. If it’s Japanese beetles, they’ll also spend this time eating all your garden plants.

Then, in August or September, those eggs begin to hatch into a new wave of grubs. These grubs are very young and fragile, making it the perfect time for treatments. At the same time, all the adult beetles die out after living for around 40 days.

The second wave of grubs will feed on your lawn’s roots until around October, when the weather starts to get cold. They go underground to spend the winter. Next spring, those grubs will come out again, and the cycle will repeat.

Note: While grubs are most active during their larval stage, typically in late summer and early fall, it’s essential to monitor your lawn throughout the year for signs of damage. Early detection allows for prompt action and better outcomes in controlling the infestation.

How to prevent grubs in your lawn

Preventing grub infestations is often more manageable and cost-effective than treating them. Here are some preventive measures you can take:

Preventive pesticides for grubs

Person using sprayer with an herbicide, fertilizer or pesticide on a lawn

If you’ve had grubs before or suspect that you have, it’s a good idea to use preventive pesticides for the next few years to ensure they don’t come back. Look for grub pesticides with the residual chemicals imidacloprid, thiamethoxam, clothianidin, or chlorantraniliprole.

Note, though, that preventive pesticides will have no effect on grubs currently living in your garden.

Best time to use preventive pesticides: For these pesticides to be effective, you have to apply them before grub infestation. Apply them in June or July to prevent grubs from hatching in the fall.

Natural ways to prevent grubs in your lawn

There are steps you can take to make your lawn less attractive to adult beetles when they’re laying eggs. If you can prevent them from laying eggs on your lawn, you won’t have grubs in the fall. Even if you have a few, there won’t be enough to cause significant damage.

The time to think about grub prevention is June through July – when adult beetles emerge from the soil and begin laying eggs.

1. Let your lawn dry out

Did you know your lawn can survive a few months of drought? But beetle eggs can’t. They need moisture to survive. If you stop watering your lawn during adult beetle season, you’ll see far fewer grubs come fall.

Stop watering your lawn beginning in June and continuing through September to exterminate grubs before they even have a chance to hatch. Your lawn will go dormant during this time, which means it will turn brown. But it should spring back to its normal self when you resume watering.

2. Dethatch every year

Thatch is a hotspot for pests. Some thatch is healthy for your lawn, but too thick of a layer will attract grubs and other common lawn pests.

illustration explaining thatch on grass
Infographic by Juan Rodriguez

When you dethatch your lawn every year, you are making it less attractive as a breeding ground. A lawn with a healthy thatch layer attracts fewer pests than one with excessive thatch.

3. Proper lawn care

A healthy lawn also can prevent these pests from invading your lawn. Adult beetles have a harder time laying their eggs when thick grass blocks access to the soil.

How can you keep your lawn lush and healthy? Here are some basic proper lawn care practices:

  • Mow your lawn to the right height for your grass type. Too long or too short, and you could affect the grass’s health.
  • Fertilize your lawn on a regular schedule to boost healthy growth.
  • Don’t overwater your lawn. Overwatering is even worse than underwatering in most cases. Too much water attracts pests and leads to weak roots, which are more susceptible to grub damage. Most established lawns only need an inch of watering per week.

When your grass is healthy, it develops a deeper, stronger root system. That way, your lawn can resist damage from grubs even if you aren’t successful at preventing them.

These tips might seem like a lot of work, but you aren’t alone on your journey to a healthier lawn. If you’ve already used all methods, but they’re still not enough to control the grub population in your lawn, you can opt for integrated pest management instead.

FAQ about getting rid of grubs

Will grubs go away on their own?

Sort of, but not really. Grubs burrow deep underground every winter, so they won’t actively damage your lawn for a few months. But the following spring, they’ll emerge in the soil again, just as hungry as ever.

Which grass types are grub-resistant?

Warm-season grasses resist grub damage better than cool-season grasses. Tall fescue is the best grass type for resisting grubs.

What happens if I don’t get rid of grubs?

If you don’t address a grub infestation, the damage can escalate, making your lawn vulnerable to other pests, diseases, and environmental stressors. Furthermore, a severe infestation can devastate your landscaping to the point where reseeding or resodding may become necessary, incurring additional costs and effort.

Stop grubs from taking over your lawn

Once grubs get their tiny hands on your lawn, they won’t let go unless you make them. They’ll keep coming back every spring, destroying your lawn’s root system all over again with each new generation.

So, make this year the last one for the grubs in your yard. Take steps as soon as possible to prevent and control grubs, and you’ll save yourself a headache in the coming years.And, if grubs are still turning your lawn brown after you’ve tried everything, call a lawn care professional to help get rid of grubs in your lawn.

Main Photo Credit: James Mann | Flickr | CC BY 2.0

Melanie Joseph

After discovering her passion for writing through her beauty blog, Melanie left her engineering job in California, became a writer, and never once looked back. When she isn't writing, she loves dipping in the pool, tending to the garden, or doing simple home improvement projects.