Best Grub Worm Killer

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Have you noticed patches of your lawn turning brown and dying, even though you’ve taken care to water and fertilize the grass?

If you have, the problem is most likely caused by grub worms. Phyllophaga, to give the grubs their scientific name, are the larvae of several species of the scarab beetle.

The beetles lay their eggs in your lawn, where they hatch, and the larvae begin to feed on the roots of the grass plants that make up your lawn. The damage caused by the munching grub worms eventually kills the grass plants, leaving the soil around them loose and fragile and covering your once-lush lawn with patches of withered, brown grass.

So, how can you save your lawn from certain death and damage this summer?

Let A Pro Handle It.

Get a no obligation quote from a pest control pro near you:

In this article, we review five of the best grub worm killer products that are available on the market. We also look in detail at the steps you can take to protect your grass from this destructive garden pest, and we’ll answer some frequently asked questions about the dreaded grub worm.

Best Grub Worm Killer

The most effective way of killing grub worms is to use a powerful insecticide. Here are five products that are proven to do the job quickly and efficiently.

Scotts GrubEx, 10,000-sq ft. (Grub Killer & Preventer)

This USA-made grub worm killer is a very powerful product that contains chlorantraniliprole as its active ingredient. Use the grub killer in early summer to kill off the grubs before they hatch and begin to damage your lawn.

Scotts GrubEx - Grub Killer and Preventer - 10,000 sq ft - kills White Grub, Japanese Beetle Larvaw, and More As Listed (Sold in Hi, NY)
  • One Application Kills and Prevents All Season (up to 4 months) - Guaranteed; Satisfaction guaranteed or your money back
  • Kills 25% More Grub Types (vs. original GrubEx)
  • Use annually to help control Japanese beetle infestations

Last update on 2018-12-10 / Affiliate links / Images from Amazon Product Advertising API

What we like:

  • The product works on many species of turf-damaging insect larvae, including grub worms.
  • The effects of the product last for up to four months.
  • GrubEx is easy to use; simply apply the product to the lawn, using the sprayer provided, and then water the lawn to moisten the soil and activate the chemical.

What we don’t like:

  • Some users have complained that GrubEx kills or damages earthworms. Earthworms are essential for a healthy lawn, so any casualties are not a good thing. However, the manufacturers insist that the product does not harm earthworms or soil bacteria.
  • If you live in New York State, you won’t be able to buy or use this product.

Bayer Advanced 700740S 24 Hour Grub Killer Plus

Bayer’s grub killer has imidacloprid as its active ingredient. Just one application of the easy-to-use product is sufficient to kill many species of turf-attacking larvae, including grub worms.

Sale
Bayer Advanced 700740S 24 Hour Grub Killer Plus, Granules, 10-Pounds
  • Excellent turf rescue formula - kills Grubs overnight
  • PLUS kills Ants, Billbugs, Chinch Bugs, Crickets, Cutworms, Earwigs, Grasshoppers, Leafhoppers, Millipedes, Mole Crickets, Pill bugs, Scorpions, Sod Webworms, Sow bugs and Ticks
  • Kills Grubs in 24 hours

Last update on 2018-12-10 / Affiliate links / Images from Amazon Product Advertising API

What we like:

  • Bayer’s product kills grub worms for the whole season after just one application.
  • The product covers 5,000 square feet, making it excellent value for money.

What we don’t like:

  • Some users reported that two applications were necessary, once in spring, and then again in fall to be fully effective.

Roundup For Lawns Bug Destroyer

Roundup is a well-known maker of weed and pest killer products for use in domestic gardens. The bug destroyer granules kill over 100 species of insects that can damage your lawn, both above and below ground.

Sale
Roundup For Lawns Bug Destroyer Granule 10 LB
  • Kills listed insects by contact and keeps killing for up to 3 months
  • Kills 100+ listed insects
  • Kills above and below the lawn's surface

Last update on 2018-12-10 / Affiliate links / Images from Amazon Product Advertising API

What we like:

  • The product is easy to administer, using a fertilizer broadcaster.
  • Effects can be seen almost immediately. Any living grubs soon die off and adults landing on the grass are killed too, preventing a reinfestation.

What we don’t like:

  • This product does work-out slightly more expensive than some of the other comparable options.

Sevin Lawn Insect Granules

Sale
Sevin Lawn Insect Granules, 20 Pounds
  • Large-Scale Pest Protection. Large-Scale Results
  • Kills Over 30 Listed Pests
  • Use on Lawns, Ornamentals and Around Homes

Last update on 2018-12-10 / Affiliate links / Images from Amazon Product Advertising API

Sevin’s insect granules are a best-selling brand. The granules are effective against over 30 species of lawn pests, including grub worms. After spreading the granules, water the area to activate the insecticide.

What we like:

  • The granules are very quick and easy to apply, using a broadcast spreader.
  • You can safely use this product around fruit and veg plots without that your produce will be poisoned.

What we don’t like:

  • Some users found that the Sevin duster product was more effective than the granules. However, using the dust will work out more expensive than other products if you have a large area to cover.

Bonide Products 60360 Insect/Grub Killer

Bonide is another best-selling lawn pest killer on Amazon. This product uses a combo of imidacloprid and lambda-cyhalothrin: two powerful insecticides that will quickly and effectively dispatch grub worms and 40 other species of lawn pests.

Bonide Products 60360 Insect/Grub Killer, 5M
  • Insect and Grub Granules
  • Control turf damaging insects above, and below the ground with one product
  • Kills grubs, and over 40 additional insects including earwigs, fleas, ticks, pill bugs, and more

Last update on 2018-12-10 / Affiliate links / Images from Amazon Product Advertising API

What we like:

  • The product kills insects above and below ground, which is great news if your lawn is plagued by ants, as well as grub worms, during the summer.
  • Bonide is quick and easy to use, and the effects last for several months.

What we didn’t like:

  • Although this grub worm killer works great on the bugs, it’s also toxic to pets and people. So, you’ll need to keep Fido and Kitty indoors immediately after you’ve applied Bonide to your grass.

Grub worms? How do you know?

So, your lawn appears to be dying. There are brown, withered patches everywhere. But how do you know that underground pests are to blame and not some form of grass disease?

Well, if the damage to your lawn has occurred in an area that’s shaded by trees or bushes, it’s not likely to be caused by grub worms. These pests need healthy grass roots to feed on. Grass growing in the shade is less likely to be robust and healthy; hence the grubs won’t bother with it.

If grub worms are to blame, locating the culprit is easy. Take a sharp trowel or spade and lift a small area of the damaged turf. Underneath you will most likely discover a gathering of grub worms. Grub worms have a very distinctive C-shaped, cream-colored body, brown head, and six stubby legs. These destructive pests can grow up to two inches in length.

Raccoons and skunks can provide another pretty reliable indicator that you have grub worms in your lawn. Look for signs that nocturnal wildlife has been digging in your grass overnight, looking for food.

If you notice that patches of your lawn feel “spongey” underfoot, you may have an infestation of grub worms in that area. The squashy feeling happens because the grass root system has been weakened by the munching grubs, hence the ground is no longer as firm as it would be with the grass root mat supporting it.

Why is your lawn a grub worm nursery?

The adult beetles that are responsible for laying their eggs in your lawn are pretty choosy about where they want their offspring to grow up. In general, sunny, moist lawns are preferred. Therefore, if you look after your lawn and water it regularly throughout the summer, the lush turf will be a grub worm “des res.”

That’s why your neighbor’s parched dustbowl of unkempt, threadbare grass will certainly not have a population of grub worms living in it.

Preventative measures

Adults lay their eggs in the soil during the summer months. As soon as the grubs hatch, they begin to feed on the grass roots. When the weather cools down, and winter arrives, the grub worms descend deep down into the soil away from damaging frost. As the weather warms up again in the spring, the grub worms head back to the surface to feed until they mature.

The most effective strategy for lawn protection is to tackle the problem before the larvae hatch, i.e. in mid-summer. You may have to treat your lawn again in the following spring, to kill off any grub worms that survived the winter deep underground. That done, your lawn should remain pristine and free-from the damage caused by these nuisance pests.

What to look for when choosing grub worm killer

When choosing grub worm killer, look for certain chemicals to be included in the list of constituents. Highly-effective insecticides include:

  • Imidacloprid
  • Thiamethoxam
  • Halofenozide
  • Clothianidin
  • Chlorantraniliprole

All these chemicals will kill newly hatched grub worms before they have a chance to start feeding on your grass plants and should be used in early summer.

Don’t use preventative compounds such as thiamethoxam, clothianidin, or imidacloprid during the spring. Use them only in June or July. If you apply them in the spring, some of the chemicals will leach through the turf or just break down, rendering the insecticide ineffective in July when the grubs hatch.

The chemicals, carbaryl, and trichlorfon that are considered to be curative treatments. These are short-lived compounds that will kill grub worms at every stage of their life cycle. These two insecticides are pretty much the only viable options you have if high numbers of grub worms are found in the fall and before early May.

How to safely apply grub worm killer

Once you’ve chosen the most appropriate grub worm killer for your lawn, be sure to apply the product correctly and safely, using these helpful tips:

  • If your chosen product contains thiamethoxam, clothianidin, or imidacloprid, it could be harmful to bees. Mow your lawn before you spread the grub worm killer to remove any flowering weeds in the grass. Mowing before application of the product will ensure that foraging bees won’t land on any contaminated flowers where they could ingest the toxic chemicals.
  • Always wear rubber boots and rubber gloves when applying pesticides to your lawn. Be sure to wash your boots thoroughly when you’ve finished to clean off any chemical residue.
  • If you’re using a spray, wear a face mask. Wait for a calm, windless day to apply the pesticide and try to avoid overspray onto nearby flowers and vegetables.
  • After applying the grub worm killer to your grass, irrigate the area with at least half an inch of water. Irrigation is necessary to activate the chemicals in the product and wash them down into the soil where the grub worms are hiding.
  • Allow the grass to dry thoroughly before allowing children or pets onto the treated area.
  • Always store all insecticide products in a securely locked cupboard that’s not accessible to children or pets.

Note that you’ll need to dress your lawn with a suitable fertilizer after you’ve treated the grass with insecticide. Fertilizer is essential to allow the grass plants to recover from grub worm damage and to protect the plants from further harm.

Frequently Asked Questions

In this part of our Buyers’ Guide, we’ll answer some of the most commonly asked questions that people have about grub worms and how to control them. If you can’t see the information you need in our guide, drop us a mail, and we’ll do our best to answer your question!

Q: Can you get rid of grub worms naturally?

A: Yes, there are ways of tackling grub worms without using chemicals. However, pesticides do tend to be more effective, especially if you have a large grub worm infestation.

Using milky spore on your lawn is a natural way to kill grub worms and keep your turf clear for up to 10 years. Spread milky spore on the grass in the early fall.

Q: My dog eats grub worms! Are they poisonous?

A: If your dog is eating grub worms in your garden, keep Fido away from these pests. Grubs aren’t generally toxic if eaten, but only if they’re taken from sterilized soil that doesn’t contain chemicals or fertilizer.

Q: Do grub worms bite humans?

A: No. Grub worms are completely harmless to people; it’s only your grass plants and veggie roots that need to be worried!

Q: What are nematodes and can they kill grub worms?

A: Beneficial nematodes are the grub worm’s sworn enemy! These microscopic, soil-dwelling worms produce bacteria that spread through the soil, infecting and killing the grub worms. You can buy nematodes in liquid form or mixed with water. Simply spray the tiny assassins onto affected areas of your grass, and watch the grub worms slowly disappear.

Wrapping it up

If your lawn is looking threadbare, patchy, and brown, the damage could be caused by grub worms.

The best way to get rid of this harmful garden pest is to use a powerful pesticide such as the products we’ve featured in our Buyers’ Guide. We especially like Scotts GrubEx. It’s not only highly effective, but it’s also easy to use, and it’s made in the US to exceptionally high safety standards.

You can protect your lawn from attack by grub worms by using a good preventative treatment in mid-summer. Say goodbye to sad, withered grass and say hello to a lush, green lawn that will be the envy of all your neighbors this summer!