Grubs in the Lawn – How to Identify and Kill Grubs

Is Your Lawn Dying Before Your Eyes? Grubs Might Be the Culprit! You water your lawn, fertilise it, and do everything right—so what’s with the ugly brown patches appearing out of nowhere? If your grass peels up easily like a loose carpet, you’ve got a hidden enemy beneath the soil: Lawn Grubs, da da da!

These tiny white larvae are silently destroying your lawn from the roots up, leaving you with dead, patchy grass that won’t recover. Even worse? If left untreated, they invite an army of predators like raccoons and birds that will tear up your yard looking for a feast.

The good news? You can stop them before they do any more damage. In this guide, you’ll learn how to identify grubs, understand their life cycle, and apply the right treatment at the right time. Plus, I’ll show you how to repair your lawn so it looks lush and healthy again.

Let’s get started—before more of your lawn falls victim to these underground destroyers!

What Are Lawn Grubs? (And Why They’re a Big Problem)

Lawn grubs are the larvae of beetles—tiny, C-shaped pests that live just beneath the soil surface, feeding on grassroots. These little invaders may look harmless, but they’re one of the most destructive lawn pests you’ll ever encounter.

Common Types of Lawn Grubs in the U.S.

Not all grubs are created equal. The most common culprits responsible for destroying American lawns include:

• Japanese Beetle Grubs – Found across much of the U.S., these grubs are the larvae of the infamous Japanese beetle, which also damages plants and flowers.
• European Chafer Grubs – A major problem in the Northeast and Midwest, these grubs are especially destructive to cool-season grasses.
• June Bug (June Beetle) Grubs – More common in the southern states, these grubs attack warm-season grasses and can cause severe damage.
• Masked Chafer Grubs – Found nationwide, these grubs are active in both warm- and cool-season lawns.

What Do Lawn Grubs Look Like?

Lawn grubs are easy to identify if you dig just below the surface of the affected grass. They have:

• A white, C-shaped body
• A soft, plump texture
• A brownish or orange head
• Six tiny legs near the head

Next, let’s look at where grubs are most likely to infest your lawn, whether you have cool-season or warm-season grass.

Where Do Lawn Grubs Live? (Warm-Season vs. Cool-Season Lawns)

Lawn grubs aren’t picky—they’ll feast on almost any type of grass.

Grubs in Cool-Season Lawns (Northern U.S.)

Cool-season grasses thrive in northern states where summers and winters are mild. The most common cool-season grasses include:

• Kentucky Bluegrass
• Perennial Ryegrass
• Fine and Tall Fescue

When do grubs attack?
Grubs are most active in late summer and early fall, just after beetles lay their eggs in the soil. By the time you notice dead patches in September or October, the damage has already been done.

Where do they live?
In cool-season lawns, grubs typically burrow 1-2 inches below the surface, where they munch on the root system and weaken your grass before winter dormancy.

Grubs in Warm-Season Lawns (Southern U.S.)

Warm-season grasses dominate southern states, where summers are longer and hotter. Common types include:

• Bermuda Grass
• Zoysia Grass
• St. Augustine Grass
• Centipede Grass

When do grubs attack?
Grubs tend to be most active in late spring through early summer, when temperatures warm up and beetle eggs hatch into hungry larvae.

Where do they live?
In warm-season lawns, grubs often burrow deeper (up to 4 inches) to avoid heat and drought stress. This can make detection harder, as damage may not appear until the grass starts to thin out.

Why Does Grass Type Matter?

• Cool-season lawns are more vulnerable to grub damage in fall, right before winter dormancy.
• Warm-season lawns may not show grub damage as quickly, but infestations can still cause significant thinning and patchiness.
• Knowing when grubs are active in your lawn helps you apply treatment at the right time for the best results.

Now that you know where grubs live, let’s look at how to spot an infestation before it’s too late!

How to Spot Lawn Grub Damage Before It’s Too Late

Grubs don’t destroy your lawn overnight, but by the time you notice the damage, they’ve likely been feasting for weeks. The key to stopping an infestation is early detection.

Here’s how to tell if grubs are munching on your lawn.

Early Signs of a Grub Infestation

Lawn grubs feed on grass roots, cutting off the plant’s ability to absorb water and nutrients. Here’s what to look for:

• Spongy or Loose Turf – If your lawn feels soft and bouncy underfoot, it could be due to grub activity weakening the root structure.
• Grass Peels Up Easily – Try the “tug test”: grab a patch of affected grass and pull. If it rolls up like a loose carpet, exposing white C-shaped grubs underneath, you’ve got a problem.
• Irregular Brown Patches – Grub-damaged grass turns brown and dies in patches that worsen over time, especially in late summer and early fall.
• Increased Animal Activity – Raccoons, skunks, armadillos, and birds love to dig up lawns searching for grubs. If you see unexplained holes or torn-up sod, it’s a sign something tasty is living beneath the surface.

How to Check for Lawn Grubs

If you suspect grubs, do a quick inspection:

1. Choose a damaged area and cut a 1-square-foot section of turf.
2. Peel back the grass and inspect the soil underneath.
3. Count the grubs – If you find 10 or more per square foot, it’s time to treat.

Not All Brown Patches Mean Grubs

Lawn diseases, drought stress, and compacted soil can also cause dead patches. However, if your grass lifts easily and you spot grubs underneath, you’ve found the culprit.

Why Lawn Grubs Kill Your Grass (And How to Stop It)

Grubs are silent killers. Unlike surface pests, they work underground, where you can’t see them—until your grass starts dying. But why do they cause so much damage, and how can you stop them before your lawn is ruined?

How Grubs Destroy Your Lawn

Grubs target the root system of your grass, cutting off its ability to absorb water and nutrients. Here’s how it happens:

1. Grubs hatch in late summer and immediately begin feeding on grass roots.
2. As they chew through the roots, the grass becomes weak and unable to recover from stress (like drought or heat).
3. The first sign of trouble is usually wilting or browning, even if you’re watering regularly.
4. Over time, large patches of grass die off, especially in dry conditions.
5. Because the roots are gone, the turf lifts easily, peeling up like a loose carpet.

Why Some Lawns Recover Better Than Others

Not all lawns react the same way to grub damage. Here’s what makes a lawn more vulnerable:

• Shallow Root Systems – Thin or stressed lawns (especially those with compacted soil) suffer worse damage.
• Drought Conditions – Grub-damaged grass can’t absorb water, making it dry out faster.
• Overgrown Thatch Layer – A thick layer of dead grass can hide grub activity, delaying treatment.
• High Grub Populations – A few grubs won’t destroy your lawn, but 10+ per square foot will cause serious damage.

How to Stop the Damage from Spreading

1. Check for grubs using the tug test—lift a section of grass to see if grubs are underneath.
2. Water your lawn deeply to help surviving grass recover.
3. Apply a grub treatment (more on this in the next section) to kill the infestation.
4. Avoid fertilizing too soon—stressed grass needs time to heal before boosting growth.
5. Plan for lawn repair once the grubs are gone.

Now that you know how grubs kill your grass, let’s talk about the best way to kill them—above and below the soil!

Understanding the Lawn Grub Life Cycle

Lawn grubs don’t stay forever, but they always return. Knowing their life cycle helps us plan our removal strategy.

The 4 Stages of a Lawn Grub’s Life Cycle

1. Egg Stage (Mid to Late Summer)
   • Adult beetles lay eggs in the soil, usually in July or August.
   • Eggs hatch within a few weeks, right when your lawn is at peak summer stress.
2. Larva Stage (Late Summer to Fall – Peak Lawn Damage!)
   • Newly hatched grubs are small but extremely hungry, feeding aggressively on grassroots.
   • This is the most destructive stage—your lawn may start developing brown patches.
   • Best time to treat! Applying grub killer now is most effective.
3. Pupa Stage (Late Fall to Early Spring)
   • As temperatures drop, grubs burrow deeper into the soil to survive winter.
   • At this stage, they stop feeding, so grub treatments are useless.
4. Adult Beetle Stage (Spring to Early Summer)
   • In late spring, grubs emerge as beetles, mate, and restart the cycle.
   • Preventative treatments applied in late spring or early summer can stop eggs from hatching.

The Best Way to Kill Lawn Grubs – Above & Below Treatment

Once you’ve confirmed a grub infestation, it’s time to take action. The most effective way to eliminate grubs is by using a dual-action treatment that targets both surface grubs and below-ground larvae.

Why You Need an Above & Below Treatment

Most grub killers only work on one stage of the grub life cycle. But for long-term control, you need a treatment that:
✔ Kills active grubs in the soil (below-ground treatment)
✔ Prevents eggs from hatching and future infestations (above-ground treatment)

Using Dissolvable Granules (DG) for Maximum Effectiveness

The best grub-killing products use dissolvable granules (DG), which quickly break down in water and penetrate deep into the soil. Here’s why they work better than traditional treatments:

• Faster absorption – Works quickly to kill feeding grubs.
• Deep penetration – Reaches below the surface where grubs hide.
• Easier to apply – Just spread and water in—no mixing or complicated steps.

How to Apply Grub Killer for the Best Results

1. Choose the right time – Apply in late summer to early fall when grubs are young and feeding actively.
2. Mow your lawn first – Shorter grass helps treatments reach the soil more effectively.
3. Spread the dissolvable granules evenly using a broadcast spreader.
4. Water the lawn immediately – Moisture activates the treatment and helps it soak into the soil.
5. Monitor grub activity – Check for live grubs a week after treatment to ensure effectiveness.

Organic vs. Chemical Treatments – Which Works Best?

There are both chemical and organic solutions for grub control. Here’s a quick comparison:

Treatment Type	Effectiveness	Pros	Cons
Chemical (DG Granules)	⭐⭐⭐⭐⭐ (Highly Effective)	Fast-acting, long-lasting, kills grubs at multiple stages	Must be applied at the right time
Organic (Beneficial Nematodes)	⭐⭐⭐ (Moderately Effective)	Safe for pets and the environment, natural control	Slower to work, requires multiple applications

If you need fast results, dissolvable granules are the best option. If you prefer an organic approach, beneficial nematodes can help—but they take longer to show results.

Now that you know how to eliminate grubs, let’s look at when you should apply treatment.

When Should You Treat Lawn Grubs? (Timing Is Everything!)

Applying grub treatment at the right time is important. If you treat too early, the product may not reach the grubs. If you treat too late, the damage is already done.

The best time for treatment depends on whether you are trying to kill active grubs or prevent future infestations.

Best Time to Kill Active Grubs – Late Summer to Early Fall

If your lawn is already showing signs of grub damage, a curative treatment is needed. The best time to apply it is late summer through early fall, from August to October. This is when grubs are young, actively feeding, and most vulnerable to treatment.

Treating at this time works best because young grubs are easier to kill, and stopping them early prevents further damage. Late summer and early fall are also when most grub-related lawn damage occurs, making it the ideal time for intervention.

Best Time for Grub Prevention – Late Spring to Early Summer

If you have had grub problems in previous years, applying a preventative treatment can stop the problem before it starts. The best time for prevention is late spring through early summer, from May to July, before beetles lay their eggs.

Preventative treatments work by targeting eggs and newly hatched larvae, stopping an infestation before it begins. By applying treatment at this stage, you reduce the risk of needing a curative treatment later in the season.

When Not to Treat for Grubs

Applying treatment at the wrong time can lead to poor results. Winter, from November to March, is not an effective time to treat because grubs are deep in the soil and dormant. Early spring, from March to April, is also not ideal because grubs stop feeding as they prepare to pupate, making them harder to kill.

How to Know If Your Grub Treatment Worked

After applying the treatment, wait seven to ten days, then check for live grubs. If you find dead grubs in the soil, the treatment has worked. If live grubs are still present, a second application will be necessary.

Now that you know when to treat for grubs, let’s look at why they keep coming back and how to keep them from returning.

Will Lawn Grubs Come Back? (The Ongoing Battle Against Infestations)

Lawn grubs are not a one-time problem. Even after successful treatment, they can return the following year. The reason is simple: adult beetles fly in from surrounding areas, lay eggs in your lawn, and the cycle starts all over again.

While it is impossible to eliminate grubs permanently, there are ways to manage their population and reduce the chances of another infestation.

Why Do Lawn Grubs Keep Coming Back?

• Beetles Lay New Eggs Every Year – Even if you kill the current grubs, new ones can hatch the following season.
• Nearby Untreated Lawns Can Spread Grubs – If your neighbors do not treat their lawns, beetles can move between properties.
• Some Grubs Survive Treatment – Incomplete or poorly timed treatments may not kill all grubs, allowing survivors to grow into beetles and restart the cycle.

How to Prevent Future Grub Infestations

Even though you cannot stop beetles from laying eggs, you can take steps to make your lawn less attractive to them.

1. Apply a Preventative Treatment Every Year
   Using a preventative grub control product in late spring or early summer can stop eggs from hatching, reducing the chances of another infestation.
2. Maintain a Healthy Lawn
   A strong, well-maintained lawn is more resistant to grub damage. Keep your grass thick and healthy by mowing at the correct height, watering deeply but infrequently, and aerating the soil when needed.
3. Reduce Thatch Buildup
   A thick thatch layer can provide shelter for grubs and make treatment less effective. Dethatch your lawn regularly to improve soil health and allow treatments to penetrate properly.
4. Encourage Natural Predators
   Birds, beneficial nematodes, and certain insects feed on grubs. Encouraging natural predators can help keep their population in check.
5. Monitor Your Lawn Each Year
   Perform a grub check in late summer or early fall by lifting a section of turf and inspecting the soil underneath. Catching an infestation early can prevent widespread damage.

While lawn grubs are a recurring issue, consistent treatment and lawn care can keep their numbers low and prevent serious damage.

Next, let’s look at how to repair a lawn that has already been damaged by grubs.

How to Repair a Lawn Damaged by Grubs

Once grubs have been eliminated, your lawn may still show signs of damage. Grass with a strong root system may recover on its own, but large dead patches will need some extra love to regain their healthy, green appearance.

Step 1: Remove Dead Grass

Grub-damaged grass often does not recover, so the first step is to remove any dead or loose turf. Rake up the affected areas to clear out dead grass and debris. This allows new grass seed or sod to make proper contact with the soil.

Step 2: Aerate the Soil

Grubs weaken the lawn’s root system, making the soil compacted and difficult for new grass to grow. Aerating the lawn helps loosen the soil, allowing water, nutrients, and air to reach the roots. This is especially useful if grub damage was widespread.

Step 3: Apply Topsoil and Compost

Adding a thin layer of topsoil or compost improves soil health and provides a nutrient boost for new grass. Spread an even layer over the damaged areas before reseeding.

Step 4: Reseed or Lay Sod

For cool-season grasses, overseeding in early fall will help fill in the bare spots. For warm-season grasses, late spring is the best time to plant new seed or lay sod. Choose a grass variety that matches the rest of your lawn for a seamless look.

Step 5: Water and Fertilize Correctly

Newly seeded or sodded areas need consistent moisture to establish strong roots. Water lightly and frequently for the first few weeks, then transition to deep, less frequent watering as the grass matures.

Apply a balanced fertilizer to encourage strong growth, but avoid high-nitrogen fertilizers immediately after treatment.

Step 6: Monitor for New Grub Activity

Even after repairing the lawn, keep an eye out for signs of grub activity. Check for new patches of dying grass in late summer, and perform a grub check by lifting a small section of turf. If new grubs are present, apply a preventative treatment to stop them before they cause more damage.

Lawn repair takes time, but with proper care, your grass will bounce back stronger than before.

Lawn grubs are a common problem, but with proper identification, timely treatment, and ongoing lawn care, you can protect your grass from severe damage.

Now it’s time to plan your attack. Happy Hunting!

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