Brown patches in your lawn, grass pulling up like loose carpet, or animals digging holes at night—these are all signs you may have lawn grubs. These small pests live underground and quietly damage your lawn by eating the roots of the grass. If left untreated, they can ruin a healthy lawn within weeks.
The good news is that lawn grubs can be controlled. In this guide, we’ll explain what lawn grubs are, how to know if you have them, natural and chemical ways to get rid of them, and how to prevent them from coming back.
What Are Lawn Grubs?
Lawn grubs are the larvae of beetles such as Japanese beetles, June bugs, or chafer beetles. They are typically white, C-shaped worms about one inch long. These pests burrow into the soil and feed on the roots of your grass.
A few grubs are usually harmless, but large numbers can cause major damage. According to researchers at Michigan State University, a healthy lawn can tolerate up to five grubs per square foot without showing visible damage. However, if there are more than that, your lawn may start to look thin, patchy, and weak.
How To Tell If You Have Lawn Grubs
Spotting lawn grubs isn’t always easy since they live under the soil. But here are some common warning signs:
- Brown patches: Areas of dead or thinning grass that spread over time.
- Loose grass: If you can pull up your turf like a piece of carpet, it’s a clear sign the roots have been eaten.
- Animal activity: Birds, skunks, and raccoons often dig into lawns looking for grubs.
- Wilting grass despite watering: Roots are damaged, so grass can’t absorb water properly.
If you notice any of these, it’s time to test your soil.
Testing Your Soil for Lawn Grubs
The most reliable way to confirm a grub infestation is by checking beneath the surface. Here’s how:
- Choose a dry, brown patch of grass.
- Cut out a square foot of sod, about 2–3 inches deep.
- Peel it back and count the grubs.
- 0–5 grubs: Safe, no action needed.
- 6–10 grubs: Borderline—treat only if lawn looks weak.
- More than 10 grubs: Serious infestation—treatment is necessary.
Repeat this test in different areas if your lawn is large.
Natural Ways To Get Rid of Lawn Grubs
Many homeowners prefer natural methods before turning to pesticides. These solutions are eco-friendly, safe for kids and pets, and won’t harm beneficial insects. However, they usually take longer to show results.
1. Beneficial Nematodes
Beneficial nematodes are microscopic worms that attack grubs by releasing bacteria inside their bodies. This eventually kills the pests. You can buy nematodes from garden centers or online.
- Apply them in early morning or cloudy weather (they are sensitive to sunlight).
- Water the lawn before and after application.
- Reapply every two weeks if needed.
Time to see results: 1–3 years for full control.
2. Milky Spore
Milky spore is a natural bacterium that specifically kills Japanese beetle grubs. It is applied as a powder across the lawn in a grid pattern.
- Works only on Japanese beetle larvae.
- Needs warm soil to thrive.
- Can take 2–3 years for full effectiveness.
Time to see results: Long-term prevention.
3. Drying Out the Lawn
Grub eggs and larvae need moisture to survive. If you stop watering for 3–4 weeks during hot summer, many grubs will die.
- Best for drought-tolerant grasses.
- May temporarily stress your lawn, but grass often recovers when watering resumes.
- Won’t work if heavy rain occurs.
4. Neem Oil
Neem oil is a natural insecticide made from neem tree seeds. When mixed with water and sprayed on the lawn, it disrupts the grubs’ growth and feeding.
- Mix neem oil with water and apply using a garden sprayer.
- Safe for pets and children.
- Works faster than milky spore but may need repeated applications.
5. Garlic Spray
Garlic is a natural grub repellent. Crush a few cloves, mix with water, and spray over affected lawn areas.
- Simple and affordable.
- Works best for small infestations.
Pesticides To Get Rid of Lawn Grubs
If natural methods don’t work or your infestation is severe, synthetic pesticides can eliminate grubs much faster. However, they may harm pollinators like bees, so use them carefully.
Curative Pesticides
These kill existing grubs. Apply in late summer or fall when grubs are most active.
- Common ingredients: Carbaryl, Trichlorfon.
- Water the lawn before and after application.
Preventive Pesticides
These stop grubs before they hatch. Best applied in late spring or early summer.
- Common ingredients: Chlorantraniliprole, Imidacloprid, Thiamethoxam, Clothianidin.
- Won’t work if applied too late in the season.
Natural vs Chemical Treatments (Quick Comparison)
| Treatment Type | Pros | Cons | Timeframe |
|---|---|---|---|
| Nematodes | Eco-friendly, safe for pets/kids | Slow results | 1–3 years |
| Milky Spore | Long-term prevention | Only works on Japanese beetles | 2–3 years |
| Drying Lawn | Free, quick | May damage grass | Few weeks |
| Neem Oil / Garlic | Natural, safe | Repeated use needed | Weeks–Months |
| Chemical Curative | Fast results | Can harm beneficial insects | 2–4 weeks |
| Chemical Preventive | Stops new grubs | Timing must be precise | Season-long |
Preventing Lawn Grubs in the Future
The best way to deal with lawn grubs is to stop them from returning. Follow these lawn care practices:
- Keep grass thick and healthy (mow at about 3 inches).
- Don’t overwater—grubs thrive in moist soil.
- Fertilize regularly to strengthen roots.
- Reseed bare patches to discourage beetles from laying eggs.
- Test soil every 2–3 years if you’ve had grub problems before.
Professional Help for Lawn Grubs
If DIY methods don’t work or your lawn is heavily damaged, it’s wise to call a professional. Companies like TruGreen specialize in lawn grub prevention and treatment. Pest control services like Terminix and Orkin can also handle severe infestations.
Professional services usually:
- Inspect and monitor your lawn for beetle activity.
- Apply preventive treatments at the right time.
- Offer natural and synthetic options.
FAQs About Lawn Grubs
1. When should I treat my lawn for grubs?
Preventive treatments work best in late spring to early summer, while curative treatments should be applied in late summer or fall.
2. How do I know if I have grubs?
Look for brown patches, loose grass, or increased animal digging. Perform a soil test to confirm.
3. Can grubs kill my lawn completely?
Yes. A severe infestation can destroy roots, leaving your lawn thin, weak, or even dead in patches.
4. What attracts grubs to my lawn?
Beetles prefer to lay eggs in thin, moist lawns. Overwatering can make your yard more attractive to them.
5. What’s the fastest way to kill grubs?
Chemical curative pesticides give the quickest results, usually within a few weeks.
6. Are natural grub treatments safe for pets?
Yes, methods like nematodes, neem oil, and garlic spray are safe for kids and pets.
7. Do I need to treat if I only find a few grubs?
No, a healthy lawn can handle up to five grubs per square foot without showing damage.
8. Will grubs come back every year?
They can, especially if beetles return to lay eggs. Prevention and regular lawn care reduce the risk.
Final Thoughts
Lawn grubs are a hidden enemy for many homeowners, but with the right approach, you can protect your grass. Start with a soil test, choose between natural or chemical solutions based on the severity, and follow good lawn care practices to prevent them in the future.
If the problem feels overwhelming, don’t hesitate to contact a professional lawn care company. With consistent action, you can keep your lawn green, healthy, and grub-free.
