Grubs or white grubs are pests that live underneath the soil and eat grass roots, leaving your yard unattractive and brown. Aside from damaging your lawn, their existence encourages animals that feed on them as these animals are digging up patches of grass in your lawn in search of them.
Most grub worms come from Japanese beetles. These beetles lay their eggs midsummer in well sunlit areas of the lawn and tend to return to the area where they laid their eggs.
In a grub-infested lawn, using neem oil, milky spore, beneficial nematodes, or borax with homemade grub killer are among the natural ways to eradicate the annoying white grubs in your yard.
To restore the dead patches, plant new grass seed, overseed the lawn from early spring to summer, or refill the bare area with sod.
In this article, we will talk about grubs, also often called white grubs, their effect on your lawn, and how to naturally get rid of them. We will also shortly discuss how to restore dead and bare spots in your lawn caused by grubs.
What are Grubs?
Grubs are also called white grubs. They are the larvae forms of beetles such as Japanese Beetles, June “bug”, and European Chafers. Grubs are white, soft-bodied, and C-shaped creatures with legs near their heads.
They live near the surface of the soil and feed on grassroots and organic matter in the soil. By their presence, they turn sections of your lawn brown and dead.
Grubs eventually turn into large beetles and sprout from soil to mate and lay eggs again. Depending on the soil temperature and moisture, grub eggs hatch within two weeks after being laid during mid to late summer.
Grubs begin feasting on grassroots right after hatching, and the peak for root munching is in early fall. They are typically eight inches in the northernmost areas below the soil surface, but burrow deeper before winter.
Life Cycle of Grubs
- Grubs have an annual life cycle.
- Females beetles dig into the soil and lay eggs in the grass root zone during spring.
- Once they hatch, the first two larval stages feed in the grass root zone for three weeks.
- The third larval stage feeds during summer, where lawn damage is visible.
- During winter, they burrow deeper into the soil.
- The pupation happens in pupal cells three to six inches underground in the spring and early summer.
- Adult forms will emerge after three weeks. Grubs will then turn into large beetles.
Are Grubs Bad for Your Yard?
Yes, grubs are harmful to your yard, although it depends on the extent of the infestation. Grubs damage your lawn by eating the grassroots and organic matter in the soil. They then grow and transform into beetles and eat the leaves of your plants.
Here are some signs of grub infestation:
- Damaged lawn and dead patches of grass – You’ll notice brown patches or dead spots in your lawn as the grass starts to thin out, turn yellowish brown, then die. This happens when there’s grub infestation that feeds on roots, killing your lawn.
- The lawn feels spongy when walking on it – Grubs damage the roots of your grass, making it easy to pull and roll up the grass. Conducting a tug test on your grass is one way to see if the grass pulls up easily.
- Skunks, birds, or moles are digging up your grass – These animals feed on grubs and other insects found in your lawn. If there’s an increase in activity of this wildlife, it could be a sign of a grub infestation.
- Droopy leaves – droopy leaves and grass is another sign of grub infestation in your lawn. Since grubs munch on the roots of vegetation, their activity then causes the sudden death of grass, flowers, or plants.
If you’re still unsure, inspect your lawn to confirm if there’s grub and to what extent is the infestation. A healthy lawn can easily support a population of zero to five grubs and as many as nine grubs per square foot.
Search the lawn by digging 1-square-foot sections of the sod and 2 to 4 inches deep in the late summer. If they are present and feeding, follow these treatment guidelines based on the number of grubs you are dealing with:
- 0 – 5: No need for treatment.
- 6 – 9: No need for treatment unless animals are scavenging to feed on them. In a wide yard, treat the highly visible and used areas, but not the “back 40” section. An unhealthy and stressed lawn will most likely require treatment.
- 10 or more: This amount of grubs will mostly create visible damages to your lawn. Plan a treatment.
While the sections of your lawn are lifted, pick up the grubs and throw them in a can of sudsy water. Water your lawn right after replacing them.
Natural Ways to Get Rid of Grubs
The best time to treat grub worm infestation is in late summer to early fall. During these seasons, grub worms are still small and near the surface. Once you spot them on your lawn, you have to get rid of them right away.
During spring, grub worms aren’t easy to treat because they are large and don’t need feeding. In this case, insecticides are ineffective against them. Plus, rainy weather will make the treatment difficult as it can be washed off.
Here are natural treatments to get rid of grubs in your yard:
- Neem Oil
Neem oil makes good natural pesticides due to its insecticidal properties. It works as a repellent against lawn grubs and Japanese beetles. To use neem oil, mix it with water and spray it on a grub-infested lawn.
- Milky Spore
Milky spore is a bacterial disease that effectively treats lawns infested by lawn grubs. It is also environmentally safe. To use this, apply spores to your affected lawn and let white grubs eat it. As they ingest the bacteria, grubs get infected, die, and decompose, and more spores are released into your soil. This process prevents further lawn grub infestations.
Apply a tablespoon of milky spore bacteria with fur feet spacing from each deposit. Do not use a garden spreader or any kind of spreader in this process. Then, lightly water the treatment for 15 minutes.
Milky spore is one of the best natural treatments for grub infestation. It usually provides grub control for more than 15 years. However, the outcomes aren’t immediate since it takes time for a disease to develop to full effectiveness in your lawn.
In colder climates, results will come after a few seasons. The negative aspect of milky spore is that it only eliminates grubs, and no other species.
- Feed your chickens
If you suspect the presence of a grub infestation in your yard, chickens can act as a natural treatment. Simply release them loose in your yard, and they’ll start digging for grubs. This process is great to help your soil work up.
You could also dig up the grub yourself and have it fed with your chickens as a treat.
- Limit irrigation
Grubs require moisture to survive. Thus, to decrease their population, do not provide them with moisture. This can be impossible to do since grubs can be found in flower beds and vegetable gardens. However, if you have a grass lawn that goes dormant every summer and recovers once water is reintroduced, use this opportunity to kill grubs.
- Encourage birds to hang out in your yard
Attract birds with bird feeders, birdbaths, and birdhouses. Birds will help decrease the grub population in your yard by dining on them. You can also dig and spread the grubs on top of the ground for birds to eat them.
- Homemade grub treatment
Making a homemade grub treatment is a great way to discourage grubs in your yard. Mix dish soap with lemon juice, mouthwash, and water in a spray bottle. You can also mix water and garlic or chili peppers to create a pest-repellant spray.
This method discourages beetles from laying their eggs throughout your yard. Only apply this homemade grub treatment when necessary since beetles lay their eggs during summer. The recommended application of this treatment varies based on location and weather.
- Beneficial nematodes
Nematodes are tiny, parasitic worms that can kill all kinds of garden pests, including lawn grubs. They offer an organic, natural, and safe way to eliminate grubs without harming you, your family, or your pets.
Make sure to buy these microscopic living creatures from a reputable store.
Also, it is best to apply nematodes right after you buy them. Avoid exposing them to direct sunlight for they can be sterile. To use them, carefully follow the instructions on the packaging.
Here’s how to use beneficial nematode to naturally eradicate grubs:
- Choose beneficial nematodes that work great against grubs.
- Mix the beneficial nematodes with distilled water.
- Water your lawn sufficiently to keep it moist.
- Spray the beneficial nematodes in the evening on a grub-infested lawn.
- Homemade grub killer with borax
Another way to get rid of grubs is to make a homemade grub killer with borax. Borax contains boron, and its excessive use can kill your plants and grass. Repeated use of borax grub killer in your flower beds and lawn will prevent anything from growing in it. Use this option sparingly to keep your plants and grass thriving.
To use borax, mix it with warm water and pour it into a spray bottle. Distribute the borax-water solution by spraying it onto the grubs. Other mixtures for borax grub killers include onion, garlic, or pepper, together with warm water.
- Dethatch and aerate your lawn
Another way to eliminate grubs in your lawn is to aerate it. Grubs live in the topsoil during late summer and early fall. They then return to the soil during the pupal stage in spring. Aerating your lawn during these seasons can eradicate grubs living near the surface of your soil.
Dethatching is another important process if you want to eradicate grubs naturally. Leaving a thick layer of thatch gives the grub a shelter where they can lay their eggs. Removing the thatch in your lawn will keep away beetles and grubs.
Thatching also prevents treatments from penetrating the soil effectively. Dethatching your lawn is best done before applying milky spore, nematodes, and other natural solutions.
- Replace your natural lawn with synthetic turf
Synthetic turf is one of the best options to get rid of grubs and other pests without applying harmful and toxic pesticides. Replacing your natural lawn with artificial grass decreases the population of grubs that destroy your lawn.
Artificial grass brings about some great benefits, like getting to enjoy a lush and evergreen lawn throughout the year. Plus, it doesn’t require mowing, watering, aerating, weeding, edging, and other maintenance needed to preserve a natural and healthy lawn.
It is recommended to try natural treatments before moving up to pesticides. Pesticides contain toxic and harmful chemicals that can affect the health of your family, pets, bees, wildlife, and groundwater.
Fixing Grub Lawn Damages
Dead patches caused by a grub infestation in your lawn make your yard unattractive. There are options to fix and restore your lawn, and make it lush and healthy-looking. If the damages are severe, it may be hard to revive the grass.
Consider removing the dead patches and planting new grass on bare areas. Here are general options to repair a damaged lawn:
- Rake the dead grass and till the soil. Plant new grass seeds in bare areas.
- If the grass isn’t completely dead and the bare areas are small, overseed the lawn from early spring to summer.
- If you don’t like waiting for new grass to grow, refill the bare areas with sod.
Once you know how to detect grub worms and get rid of them, you’ll be ready and well-equipped to effectively treat the infestation.
Preventive measures and pest control are the best ways to stop the grub infestation that damages your lawn. If you’ve come across a grub infestation in the previous years, make sure to put down preventative natural treatment in the early spring to stop the damages early.